Telephone-based Diet and Exercise Coaching and Weight Loss

T H E
P ß © Cá] ® IT 0 @ M
(g D g IN) © g
Weight Control
Telephone- Based Diet and Exercise Coaching and
a Weight-L •ss Supplement Result in Weight and
Fat Loss in 120 Men and Women
Larry A. Tucker, PhD Amy J. Cook, MS; Neil R. Nokes, MPH; Troy B. Adams, PhD
PURPOSE
Abstract
Purpose. Determine the effet ts of telephone-based coaching and a xueight-loss supplement on
the lüäght and body fat (BF) o/overwäght adults.
Design. Randomized, placet o-controlled experiment with assessments at baseline, 2 months,
and 4 months.
Setting. Community.
Subjects. Sixty ovenueight o obese men and 60 overweight or obese women, 25 to 60 years
old.
Intervention. Eleven 30-mii .ute telephone coaching sessions were spaced throughout the
study; the initial conversation lasted 60 to 90 minutes. Supplement or placebo capsules were
taken daily over the 17 tveeks.
Measures. Weight xuas measured using an electronic scale, and BF tvas assessed using dual
energy x-ray absorptiometry.
Results. Subjects taking the placebo lost 1.8 ± 3.3 kg of lueight and 0.7 ± 2.2 kg of BF,
whereas supplement users lost i tore: 3.1 ± 3.7 kg of wäght (F = 4.1, P= . 045) and 1.7 ±
2.6 kg ofBF (F = 4.4, p = . 139). Partidpants receiving no coaching lost 1.8 ± 3.3 kg of
weight and 0.7 ± 2.2 kg of BF, ivhereas adults receiving coaching lost more: 3.2 ± 3.6 kg of
)eight(F= 4.8, p= .032) a- id 1.6 ± 2.5 kg ofBF (F = 4.2, p = .044). Adults receiving
both the supplement and coach ing had the greatest losses of weight and BF, suggesting an
additive effect (F = 3.2, p — 026; F = 2.9, p = .039, respectively),
Conclusions. Both treatmen s, coaching and the supplement, viexued separately and in
combination, luorked to help subjects lose weight and BF. Adults can be educated and motivated
via telef)hone to change behavU rrs leading to weight loss, and a lueight-loss supplement can be
included to increase success. (/ m J Health Promot 2008;23[2]:121-129.)
Attaining and maintaining a healthy
weight has become a significant problem for most adults. This problem is
especially prevalent in the United
States, where it is esdmated that 66% of
adults are overweight or obese.'
Overweight and obesity have dramadc health consequences. Adults
with a body mass index (BMI) of 25 or
greater are considered at risk for
developing diseases and morbidides
such as hypertension, dyslipidemia,
type 2 diabetes, coronary heart disease,
stroke, gall bladder disease, osteoarthrids, sleep apnea, and respiratory
problems.^"'' There is also a higher
prevalence of endometrial, breast,
prostate, and colon cancers among this
segment of the populadon. Furthermore, higher body weight is associated
with increased all-cause mortality.'^"'''''
Clearly, obesity represents a major
challenge because it is both a highly
prevalent and a highly preventable
Key Words: Obesity, We ght Loss, Coaching, Education, Supplement,
contributor to morbidity and mortality.
Overweight, Prevendon Re; earch. Manuscript format: research; Research purpose:
At the workplace, obesity restilts in
intervendon tesdng/progra n evaluadon; Study design: randomized trial; Outcome
substantially
bigher health care costs
measure: biométrie; Setdnjj: local community; Healtb focus: nutridon, weight
and
absenteeism.
According to Finkel,
skill
building/bebavior
change;
Target
populadon
control; Strategy: educadoi
stein et al.,' the cost of obesity (exage: adults; Target population circumstances: geographic locadon
cluding overweight) in a company with
1000 workers is approximately
$285,000 annually. Gorsky et al.^ inLarry A. Tucker, PliD; Amy J. Cook, MS; and Nal R. Nokes, MPH, are idth the College of
dicate that over the next 25 years
Health and Human Performance, Brigham Young University, Provo, Utah. Troy B. Adams,
$16 billion will be spent treadng bealth
PhD, is with the Department of Health Promotion and Wellness, Rocky Mountain University of
problems stemming from overweight
Health Professions, Provo, Uta I.
women in the United States. Eurther,
in a review by Scbmier et al.,'' it is
Send reprint reqttests to Larry i . Tttcker, PhD, 237 SFH, Brigham Young University, Provo, UT
84602; [email protected].
pointed out that health care costs in
the workplace are consistently higher
77ii.v ynanuscñpt xtias submitted May 16,2007; rexri.sions xuere requested July 17, September 12, and September 27, 2007; the,
among heavy employees compared
manuscript xuas accepted for pubtication ictoberB, 2007.
with their normal weight counterparts.
Copyright © 2008 by American Joumal i Health Promotion, Inc.
Further, according to Tucker and
0S90-1111/08/15.00 + 0
November/December 2008, Vol. 23, No. 2
121
Friedman,'" who re\'iewed 10,825 employed adults from numerous workplaces in the United States, obese
employees are more than twice as likely
to suffer from high-level absenteeism
tban lean workers. In a 2-year prospective sttidy incltiding mostly young
employees, Tticker and Clegg" showed
that obese workers were 1.7 dmes more
likely to have high health care costs
(>$5000) than nonobese employees.
Because the majority of Americans
are overweight or obese and the negative conseqtiences of carrying excess
body weight are many and diverse,
effective health promotion programs
designed to help adults lose weight are
needed. Numerous invesdgations have
shown that alteradons of diet and/or
exercise through sundry behavior
modificadon interventions can lead to
significant weight loss.'^"'* Simply stated, eadng and exercise behaviors infltience body weight, and because these
bebaviors are learned, they can be
modified. In short, adults who eat less
and exercise more typically lose weight.
Unfortunately, teaching and motivating adults to change diet and
exercise behaviors leading to significant weight loss is a daundng task.
Moreover, in a worksite environment,
the resources necessary to accomplish
such a goal are significant. However,
there may be a reasonable solution.
Few, if any, studies have evaluated the
extent to which periodic coaching over
the telephone can be used as an
effective weight-loss strategy. Given the
wide tise of cell phones, allowing
individuals to be connected to a weightloss coach while in almost any environment, and given the fast pace of
our society, which limits the amount of
free time adults perceive that they
have, weight-loss coaching via telephone may be helpful in reducing this
big problem. Overweight adtilts who
need help losing weight but cannot
find dme to attend educational seminars or self-belp workshops or to visit
with a coach in person can probably
find time to work with a weight-loss
counselor over the telephone. This
strategy requires less time and travel
than personal visits, making it attracdve to many overweight adults and also
to worksite health promotion programs, which are often understaffed
and low in resources.
122
American Journal of Health Promotion
Although it is difficult to argue with
the weight-loss success that typically
accompanies significant changes in
diet and exercise habits, many adults
feel that they need extra help.'"'^" As
a consequence, many weight-loss supplements have been developed.''•'•^"
Unfortunately, the effectiveness of
weight-loss supplements is rarely evaluated using sound methods. Although
prescription drugs are regulated and
mtist be shown to be effective employing the strictest sciendfic invesdgadons, supplements are not regulated
and do not require scientific investigadon. Hence, consumer beliefs regarding the effectiveness of most weightloss supplements are probably based
more on advertising and anecdotal
ddbits than on science and research.
Logic suggests that a sotind approach to promoting weight loss
among adults would be to combine two
weight-loss strategies that approach the
challenge from different angles, one
based on traditional behavior change
methods (only using the telephone to
edticate and motivate conveniendy)
and the other using a weight-loss
supplement to help with the process.
Based on this model, the ptirpose of
the present study was to evaluate the
effectiveness of two interventions on
weight and fat loss: personal weightloss coaching via telephone and
a weight-loss supplement. Specifically,
the objective was to determine the
extent to which personal weight-loss
coaching and a weight-loss supplement, considered individually and in
combination, influence changes in
body weigbt and body fat over
2 months and 4 months, compared
with placebo use and no weigbt-loss
coaching, employing a randomized,
experimental design. A secondary objective was to determine the extent to
which gender played a role in the
effecdveness of the telephone coaching and the supplement.
METHODS
Design
The study was a placebo-controlled,
randomized experiment lasdng
17 weeks. Participants were assessed at
baseline, after 2 months, and after
4 months to allow the first-half and
second-half effects of the treatments to
be evaltiated, as well as the effects over
the full 17 weeks. A 2 (supplement:
yes/no) X 2 (coaching: yes/no) X 2
(gender: male/female) X 3 (dme:
baseline/midtest/posttest) factorial
design was employed. Randomization
was stradfied or blocked to afford
equal numbers of men and women in
each experimental condidon. In short,
the 128 pardcipants were split into two
groups based on gender, 64 men and
64 women, and then the men and
women were randomly assigned separately to the two different treatments,
active stipplement or placebo, and
coaching or no coaching, using a random ntimbers table. Of tbe 128 subjects in tbe invesdgadon, 64 were
assigned to the supplement group (32
men and 32 women) and 64 were
assigned to the placebo grotip (32 men
and 32 women). One-half of those in
the supplement group also received
personal weight-loss coaching, and
one-half received no coaching. Likewise, one-half of those in the placebo
group received coaching, and one-half
did not. At the outset, there were 32
randomly assigned stibjects (16 men
and 16 women) in each of the four
experimental condidons: active stipplement with coaching, active supplement with no coaching, placebo with
coaching, and placebo with no coaching.
Subjects were blinded to the supplement/placebo condition. For tbe
telephone coaching condidon, those
who received weekly coaching obviously knew they were being coached;
however, stibjects not receiving coaching were not aware that a coaching
condition existed. The no-coaching
subjects believed that the study was
only evaluating a weight-loss stipplement. In this way, subjects not receiving coaching did not feel cheated
or resentful because tbey were not
receiving one-on-one help to lose
weight.
Sample
Subjects were recruited using newspaper advertisements covering approximately 25 cities surrounding
a university in the Mountain West. All
subjects completed a questionnaire
that requested information on their
medical histories and lifestyle behaviors. Inclusion criteria included: age
of 25 to 60 years, BMI betwe en 25 and
35 kg/ill'^, regular access to . telephone, and self-reported g id health
other than being overweight or obese,
Subjects were excluded fron the sttidy
if they currently smoked or lad quit
smoking in the previous 6 njonths, if
they had lost 4 or more kg cf 1
body
weight in the previous 3 mo iths, if
they were pregnant or iinten ied to
become pregnant during th( study, if
they reported drtig or alcoh (I abuse,
or if they reported having a ignificant
disease, such as cardiovascular renal,
hepadc, endocrine, gastroin estinal, or
psychologic, including eadn disorders. All subjects indicated t leir willingness to pardcipate in the study by
signing a consent form whicl had been
approved by the univeisity Ir sdttidonal
Review Board. Subjects were not paid
to pardcipate in tbe study, but they
were given a certificate allov ing them
to participate for free lor 3 nonths in
tbe weight loss clinic of the tiniversity
Wellness program after compl eting the
study, if they desired.
Measures
Dtial energy x-ray absorpti ometry
(DEXA; 4500W; Hologic In , Bedford,
MA) was used to meastire the body fat
of each pardcipant in grams. The
4500W is the same DEXA model tised
in the ongoing government- ponsored
Nadonal Health and Nutridon Examination Stii"vey. Concurrent vilidity of
the 4500W DEXA machine t sed in the
present study was established by comparing tbe DEXA body fat re: tilts to the
body fat findings produced by the Bod
Pod' employing 100 adults. The Pearson correlation between the two measures of body fat was 0.94 (/> < .0001),
and 0.97 {p < .0001) for th( intraclass
correlation.'^' A test-retest evaluation
using the same 100 adults and complete repositioning of each ; tibject
resulted in an intraclass coneladon of
0.999 (/; < .0001), indicadng that the
4500W was extremely reliabl
Body weight was meastired to the
nearest 0.005 kg (0.01 lb) using a Profit
electronic digital scale (Life; ource,
Milpitas, CA). Calibradon w; s checked
daily before data collecdon tsing
known weights. Test-retest results using
all subjects of the present stidy resulted in an intra-class correladon of
Stamped, addressed envelopes were
given to stibjects so that they could
mail in their completed logs at the end
of the first and third months of the
sttidy. Subjects were instructed to bring
tbeir latest logs with them to the 2- and
4-month assessment visits. The logs
were tised to calctilate supplement/
placebo compliance. Subjects were
contacted by telephone each month to
remind them to mail in their logs or to
come to their assessment appointments.
Stibjects were given enough of the
supplement or placebo to last 8 weeks
(i.e., undl their midtest assessments).
At the conclusion of their midtest
visits, subjects were given additional
botdes to last them undl the conclusion of the study.
0.999 {p < .0001), showing excellent
reliability.
Weight-loss Supplement
Tbe sttpplement, used to help subjects lose weight, was formtilated by
TriVita, Inc (Scottsdale, AZ). The
supplement and placebo were provided free to pardcipants and were packaged in idendcal sealed bottles. Reseaicbers at all levels, coaches, and
participants were blinded to which
botdes contained the active supplement and which contained the placebo. The codes showing which stibjects
received the supplement and which
received the placebo were held by
a third party undl all data were
collected. Botdes were idendfied with
subject numbers. One-balf of the subjects were given botdes containing the
acdve supplement, and one-haíf received the placebo. Stibjects were
instructed to take four capsules daily,
two in the morning and two in the
evening, preferably witb meals, and to
record tbeir supplement/placebo tise
on a printed log.
Supplement Mechanisms of Action
Each capsule contained 700 mg of
supplement, and the fotir capsules
together inclttded the following: vitamin B| (15 mg), vitamin Bg (10 mg),
niacinamide (SO mg), vitamin B5
(50 mg), \'itamin Bf, (2 mg), xntamin
B|¡; (1 mg), biodn (2 mg), vitamin C
(22.5 mg), vitamin D (1000 IU), dimethylglycine (100 mg), chromium
(0.05 mg), copper (0.5 mg), magnesitim (200 mg), vanadyl sulphate
(1 mg), manganese citrate (1 mg),
zinc glticonate (10 mg), indium sulphate (25 mg), Cardnia cambogia
(250 mg), Gymnema sylvestre (10:1;
100 mg), bitter melon (10:1; 70 mg),
cinnamon bark (500 mg), Poria cocos
(5:1; 100 mg), Rhizoma zingiberis (4:1;
50 mg), green tea (10:1; 100 mg),
Korean ginseng (100 mg), L-theanine
(50 mg), gamma-aminobtityric acid
(50 mg), alpha lipoic acid (110 mg).
Calcárea carbónica (12X; 10 mg), na-
trum stilphuricum (12X; 10 mg), graphites (30C1; 10 mg), nux vómica
(30C; 10 mg), lycopodium (30C;
10 mg), and glucomannan (700 mg).
The placebo was formulated to look
like the supplement but witb no active
ingredients. The same dosage was used
for the supplement and the placebo.
The formuladon of the supplement
was designed to primarily focus on
improving glycémie control, increasing
metabolism, enhancing mood, and
decreasing appedte, collecdvely leading to the goal of weight loss. The
mechanism of acdon of each acdve
ingredient is listed below.
Research shows that an extract of G.
cambóla, hydioxycitric acid, redtices
food intake and body weigbt regain,
presumably because of its inbibidng
effect on lipogenesis.'^'^ Otber research
has fotmd that G. cambogin inhibits
cytoplasmic lipid accumuladon as well
as adipogenic diffeiendadon of preadipocytes, and it inhibits expression
of an early adipogenic tianscripdon
factor that regulates adipogenesis.'^''
G. .sylvestre extracts have antihyperglycemic properdes that may help to
reduce appedte.''^'^••^'' The andhypeiglycemic properties of G. sylvest.re are dtie
to a combinadon of two mechanisms.
G. sylvestre increases the acdvity of
enzymes responsible for glucose uptake and udlizadon, and it inhibits
peripberal udlizadon of glucose by
somatotropbin and cordcotrophin.'^''
Extracts of bitter melon have been
sbown to normalize blood glucose
levels and reduce triglycéride levels.'•*'
Research indicates that bitter melon
juice leads to a redtiction in visceral fat
and slower weight gain in rats, partly
due to enhanced sympathetic activity
and lipolysis.^"
November/December 2008, Vol. 23, No. 2
123
Using a type 2 diabetic animal
model, Kim et al.^'^ found that cinnamon bark extract has a regulatory role
in blood glucose and lipid levels and
may also exert a blood glucose-suppressing effect by improving insulin
sensitivity or slowing absorpdon of
carbohydrates in the small intesdne.
P. cocos is a type of mushroom.
Numerous polysaccharides and polysaccharide-protein complexes have
been isolated from P. cocos and used as
sources of therapetidc agents.™ Among
other therapetidc properdes, polysaccharides have glucose-regulating activides, and pharmacologie research indicates that pancreadc dssues may
benefit from these polysaccharides.
They may also increase insulin output
by beta cells, increasing the availability
of insulin and facilitating the metabolism of insulin-dependent processes,
which are associated with weight reguladon and fat deposition.^'
Green tea contains both tea catechins and caffeine and acts through
the inhibidon of catechol O-methyltransferase and inhibition of phosphodiesterase.^^ Tea catechins have
antiangiogenic properties that may
help to prevent the development of
overweight and obesity.''^ Research has
showed that green tea supplementation promotes weight loss.*'
Korean ginseng may be beneficial in
weight management by improving
blood sugar control.'''* In a study using
hyperglycémie rats, ginseng extract was
found to exert its antilipolytic effects
through a signaling pathway different
than that of insulin.''''
L-theanine is a nonprotein amino
acid found naturally in the green tea
plant. Camellia sinensis?^ L-theanine
crosses the blood-brain barrier and
increases both serotonin and dopamine production, which tend to lower
blood pressure and improve mood.'""
Given that some adults eat to relieve
feelings of stress, it is postulated that
L-theanine may help with this problem.
Alpha lipoic acid enhances glticose
uptake in type 2 diabetes and inbibits
glycosyladon. Besides blood sugarregulating properdes, alpha lipoic acid
also appears to possess weight-regulating properties, exerting these effects in
the hypothalamus by suppressing appedte by inhibidng AMP-activated
protein
''^
124
American Journal of Health Promotion
Vitamin D is both a vitamin and
a hormone. It is a vitamin because the
body cannot absorb calcium without it;
it is a hormone because the body
manufactures it in response to the
skin's exposure to sunlight. Vitamin D
significantly increases the absorpdon
of calcium.^' Dietary calcium appears
to play a role in the regulation of
energy metabolism and obesity risk.''*
One study showed that 80% of morbidly obese patients presented with
vitamin D deficiencies.''^ High calcitim
diets seem to attenuate body fat accumuladon and weight gain during periods of overconsumption of an energydense diet and to increase fat breakdown and preserve metabolism during
caloric restricdon, thereby accelerating
weight and fat loss. This effect is
mediated primarily by circulating calcitriol, which regulates adipocyte intracellular calcium.'"^
Chromium polynicodnate is an essential trace mineral that helps the
body maintain normal blood sugar
levels.'"' Chromium has been studied
extensively regarding weight and fat
loss. Although findings are far from
unanimous, results show that chromium supplementation tends to slow
weight gain and aid in weight loss."*'
Glucomannan is a water-soltible dietary fiber that is derived from the
konjac root. Like other forms of dietary fiber, glucomannan is considered
a "bulk-forming laxative.'"*^ Research
has suggested that glucomannan may
promote weight loss.'*'^"'*' The evidence
suggests that glucomannan exerts its
effects by promodng sadety and fecal
energy loss, and possibly by improving
glycémie status.''^
Personal Weight-loss Coaching
The weight-loss coaching intervention included talking on the telephone
with a trained weight-loss coach once
per week for approximately 30 minutes
per session during at least 11 of the
17 weeks of the study. However, the
inidal telephone coaching session was
scheduled to last 60 to 90 minutes for
the participant and coach to get to
know each other and to allow time to
btiild a meaningful foundation from
which to work.
During the initial 6 weeks of the
study, subjects were encouraged to
pardcipate in weekly coaching sessions;
during the final 11 weeks, subjects
were asked to work with their coach
every other week. If a stibject reqtiested
an addidonal coaching session, then
an extra session was added, however,
subjects were not coached more than
once in any week. Sessions were arranged to accommodate subjects'
schedules, although most sessions were
held at the same dme and on the same
day of the week across the study.
Subjects were encouraged to make up
missed sessions as soon as possible.
The TriVita personalized health
coaching service was the foundadon of
the coaching intervention. Three
weight-loss coaches were used in the
study. Stibjects were cotinseled by the
same weight-loss coach throughotit the
entire study. Each of the three coaches
was cerdfied through the WellCoaches
program,'"' which is endorsed by the
American College of Sports Medicine.
During the telephone coaching sessions, weight-loss guidelines developed
by the American College of Sports
Medicine were used to assist stibjects.'"
In short, subjects were taught abotit the
energy balance model and the importance of expending more energy than
was constimed. They were educated to
practice self-monitoring and were
trained to become more aware of their
eadng habits and energy needs. Pardcipants were encotiraged to consume
healthy meals; avoid extreme diets; eat
smaller pordons; consume more fruits,
vegetables, and fiber; reduce junk food
consumpdon; and exercise more. As
subjects pardcipated in the program,
specific weight-loss problems and barriers tbat surfaced were discussed during coaching sessions, and possible
soludons were provided. As mtich as
possible, weight-loss strategies and diets
were customized to fit the needs and
interests of each participant. Moreover,
each telephone coaching session served
as an opportunity for participants to
report back to their coaches about
successes and failures and to be accountable for their behaviors.
Subjects in the weight-loss coaching
group were asked to keep written logs
of their coaching sessions in addidon
to their supplement or placebo use.
The same log was used for recording
both intervendons, and the logs were
returned via mail or in person so that
compliance could be monitored.
Analyses
The PASS power analysis Software
(version 6.0; NCSS, Kaysville, UT) was
used to calculate the sampk size
necessaiy to conclude the in /esdgadon
with a minimum power of 0 80 and an
effect size of 0.25. Addidond subjects
were incltided in the sample to allow
for a combined attrition anc noncompliance rate of 25% (actual tttrition
and noncompliance together was approximately 10%). Repeatec-measures
analysis of variance (ANOVA) was used
to identify the effects of supplement
use compared with placebo ase, tbe
effects of weight-loss coaching compared with no coaching, anc the
effects of gender on body w ;ight and
body fat across tbe three dn e periods
of the 4-month study. The effect of
gender was considered secondary, and
because there were no gend;r differences and gender had no effect on any
of the other relationships, the female
and male data were pooled ;
ind the
gender factor dropped from the analyses.
Because the invesdgadon ncltided
a pretest, midtest, and posttest to
enable evaluation of the short-term
effects of the treatments, as veil as the
longer-term effects, the data were
analyzed across the first and second
halves of the study separately, as well as
across the endre study. Pard il correladon was employed to determine the
extent to which group mem jership in
the second treatment infltieiiced the
treatment effects. The least-s^quares
means procedure was emplo^ied to
calculate means adjusted for differences in the potential confo lnding
variables. All analyses were performed
with SAS software (version 9 1; SAS
Insdtute Inc, Cary, NC).
An intent-to-treat strategy vas also
used with all subjects who b( gan tbe
study included in the analyse s ( n =
128). In short, pardcipants who
dropped out of the study an i those
who failed to comply with th supplement/placebo and coaching nocoaching protocols were included.
RESULTS
Participant Characteristics
Of the 120 subjects who completed
the study, 60 were men and 30 were
women. Additionally, approximately
95% of the sample was white, with the
remaining participants repordng Asian
or Hispanic ethnicity. At baseline, the
average age was 43 ± 9 years and
ranged from 25 to 60 years. At baseline, the mean body weight of the
sample was 91.3 ± 14.5 kg, average
percent body fat was 35.8% ± 6.1%,
and mean BMI was 30.6 ± 2.7 kg/m'"^.
There were no significant differences
among any of the treatment groups on
any of the outcome variables at baseline, indicadng that random assignment of subjects to groups was successful.
Compliance
A total of 120 of the 128 (94%)
original participants completed the
baseline, 2-montb, and 4-month assessments. Reasons for quitting the
study included loss of interest (five
subjects), pregnancy (one subject),
divorce (one subject), and serious
automobile accident (one subject).
None of the dropouts reported any
ailments or side effects that might have
been associated with taking the supplement/placebo.
Stibjects were required to record
their supplement or placebo use each
day on preprinted forms. The written
logs were used to identify subjects wbo
did not take tbeir capsules on a regular
basis. Subjects wbo reported less tban
70% compliance over the 4-month
sttidy were not incltided in the analyses. Of the 120 subjects who completed
the sttidy, five were identified as noncompliant because of tbeir infrequent
supplement use, leaving 115 subjects
(90% of the original sample) for the
supplement/placebo analysis. Average
supplement use compliance was 88%
± 12% witb noncompliant subjects
removed.
Records were also kept of each
telephone coaching session. Over the
17 weeks of the study, subjects in the
coaching group who did not participate in at least 11 coaching sessions
were considered noncompliant and
were dropped from the analyses. Of
the 60 subjects in the coaching group
who completed the sttidy, seven failed
to meet the 11 coaching session minimum, leaving 113 subjects (88% of the
original sample) in the coaching/nocoaching comparison. Average number of coaching sessions per subject in
the coaching group was 11.6 ± 0.7 over
the 17 weeks among subjects who were
compliant.
Effect of the Supplement
At baseline, there were no differences between the supplement and
placebo groups in body weight (F =
1.3, p= .266) or body fat (7'^ = 0.1, /; =
.818). However, tbe group by time
interacdon of the repeated-measures
ANOVA indicated that subjects in the
active supplement group lost significantly more weight (F = 4.2, p = .016)
and body fat (F = 4.5, p = .013) than
participants in the placebo group over
the three assessment periods (Table 1). Specifically, adults who took the
supplement lost 1.3 kg or 76% more
body weigbt and 0.9 kg or 132% more
body fat than their counterparts over
the 4-month study duration. After
controlling for membership in the
coaching/no-coaching groups (i.e.,
the second treatment), we noted that
differences in body weight {F = 4.3, /;
= .040) and body fat (F = 5.2, /; =
.025) remained unchanged and significandy different between supplement
and placebo users.
Mean differences in weigbt {F = 6.6,
p= .011) and body fat {F = 7.8, p =
.006) were also significant between the
supplement and placebo groups after
the first 2 months of the study. During
the first half of the study, supplement
users lost 1.3 kg more or twice the
body weight and nearly 1 kg more or
2.3 times the body fat compared with
placebo users. However, differences
between the supplement and placebo
users in body weight (F = 0.0, /; =
.865) and fat (F = O.\, p = .793) were
not significant over the last 2 months
of the study.
Using an intent-to-treat strategy, including all subjects who dropped out
of the study and all subjects who
completed the study but did not take
tbe supplement regularly (noncompliers), weakened the treatment effect.
Specifically, repeated-measures ANOVA across the baseline, midtest, and
posttest were borderline significant,
showing that subjects in the supplement grottp lost more body weight {F
= 2.4, p = .091) and more body fat (F
= 2.7, p = .073) than those in the
placebo group. Further, with all dropouts and noncompliant subjects in-
November/December 2008, Vol. 23, No. 2
125
Table 1
Effect of the Supplement and Coaching Viewec1 Separately on Weight and1 Body Fat Across the Baseline, Midtest,and Posttest
Baseline Body Weight (kg)
Midtest Body Weight i(kg)
Posttest Body Weight (kg)
Treatment
Mean
SD
Mean
SD
Mean
SD
F*
P
Supplement
Placebo
Coaching
No coaching
89.7
92.7
91.8
91.1
Baseline BF (kg)
13.7
14.9
14.5
14.9
87.2
91.4
89.4
89.7
Midtest BF (kg)
13.6
14.9
14.6
15.2
86.6
90.9
88.6
89.3
Posttest BF (kg)
14.0
15.0
14.6
15.7
4.2
0.016
3.9
0.022
Supplement
Placebo
Coaching
No coaching
28.8
30.1
29.4
29.6
4.8
5.2
5.1
5.3
27.6
29.7
28.4
29.0
5. 2
5..4
5..4
5..7
27.2
29.4
27.8
28.9
5.8
5.2
5.5
5.9
4.5
0.013
3.4
0.036
SD indicates standard deviation; and BF, body fat.
* F represents the F ratio for the group by time interaction for the two treatments viewed separately (i.e., supplement vs. placebo, coaching vs. no
coaching) across the three time periods. There were 53 subjects in the supplement group and 62 in the placebo group (n == 115). There were 53 subjects
in the coaching group and 60 in the no coaching group (n = 113).
eluded in the analyses and controlling
for membership in the coaching/nocoaching grotip (i.e., the other treatment), we found that stipplement
users lost significantly more body
weight (2.1 ± 2.8 kg) than placebo
users (1.2 ± 2.4 kg) during the first
half of the study {F = 3.9, p = .049).
The difference in body fat loss between
the supplement (1.0 ± 1 . 7 kg) and
placebo (0.4 ± 1 . 6 kg) groups during
the first 8 weeks was also significant {F
= 4.8, p = .031) using the intent-totreat approach.
Effect of the Coaching
There were no differences between
the coaching groups in body weigbt {F
= 0.1, p = .802) or fat (7-^ = 0.1, p =
.749) at baseline. Eurther, there were
no differences in weight loss {F = 1.65,
p = .201) or fat loss (F= 0.8, p = .460)
resulting from the three different
coaches among participants; therefore,
the coaching data were pooled. Repeated-meastires ANOVA indicated
that participants in the coaching group
lost significandy more body weight (F
= 3.9, p = .022) and fat {F = 3.4, p =
.036) than those in the no-coaching
group over the three assessment periods (Table 1). Specifically, coached
adults lost 1.4 kg or 78% more body
weight than uncoached pardcipants
and 0.9 kg or 122% more body fat than
their counterparts. With the effect of
supplement/placebo use controlled
(i.e., the second treatment), the difference in weight loss between the
126
American Journal of Health Promotion
coaching and no-coaching groups was
reduced by 0.19 kg and the results
became borderline significant (/; =
.068).
Although losses in body weight and
body fat between the coaching and nocoaching groups were significant when
viewed across the three assessment
periods (Table 1), body weigbt
changes between the two grotips during the first 2 months or first half of
the study {F = 3.4, p = .067) and body
fat changes during the last 2 months or
second half of the study were borderline significant {F = 3.1, / ; = .080).
The intent-to-treat approach weakened the effect of the coaching intervention. Across the three time periods, adults who received weight-loss
coaching did not show greater weight
loss (F= 1.9, p = .149) or body fat loss
(F = 2.0, p = .143) compared with
those who received no coaching. Similar results were revealed for differences in weight loss {F = 1.6, p = .214)
and fat loss {F = \.%p= .268) during
the first 8 weeks of the study, after
adjusdng for membersbip in the stipplement/placebo group.
Effect of the Supplement and Coaching
Comhined
The combined effects of the two
treatments are presented in Table 2.
Viewed as four separate groups or
conditions, there were significant differences in weight loss {F = 3.2, p =
.026) and fat loss (F = 2.9, /; = .039)
over the 4-month sttidy. Restilts showed
that stibjects who received both the
active stipplement and personal
weight-loss coaching over the telephone had greater body weight and fat
losses compared with each of the other
groups. None of the other groups
differed significantly from each other
over the study.
When the analysis was limited to the
first half of the study, similar findings
resulted. Specifically, the acdve supplement -H coaching group lost significandy more weight (/''= 3.6, p = .017)
and body fat (F = 3.6, p = .016) than
each of the other grotips. However,
during the second half of the sttidy,
there were no significant differences in
weight loss (F = 0.8, p = .485) or fat
loss {F= 1.0, /; = .383) among the four
groups.
DISCUSSION
According to the results, botb treatments helped subjects lose significant
body weight and body fat, viewed
separately and in combination. Specifically, regtilar use of the weight-loss
supplement resulted in greater body
weight and body fat losses compared
with placebo use. Most of the benefits
derived from taking the supplement
stirfaced within the first 2 months of
the study. During the first 8 weeks,
supplement users lost twice the body
weight and 2.3 dmes more body fat
compared with placebo tisers.
Research has indicated that early
weight loss is a strong predictor of
Table 2
Effect of the Supplement and Coaching Treatments Combined on Weight and Body Fat
Four Combined Treatment Conditions
Supplement
Coaching
Supplement +
no Coaching
Placebo +
Coaching
Placebo +
no Coaching
Outcome
Mean
SD
Mean
SD
Mean
SD
Mean
SD
F
P
Weight loss* (kg)
Fat loss* (kg)
4.4t
2.3t
3.5
2.7
2.3t
1.3t
3.5
2.2
2.1t
Lit
3.5
2.3
1.7t
0.4t
3.2
2.2
3.2
2.9
0.026
0.039
SD indicates standard deviatio n.
* Weight loss and fat loss refk ctthe average number of kg lost from baseline to the posttest 17 weeks later.
t, t Means in the same row w th the same symbol are not significantly different (p > 0.05).
success in weight-loss progrims."'
Early weight loss builds conf idence and
engenders hope concerning future
weight loss. Given the rapid weight loss
resulting from use of the st pplement.
it follows that the supplement would
be valtiable in jtimp-starting weight-loss
efforts, thereby increasing s access in
weight-loss programs.
There were no significan! differences in weight or fat loss hetween
supplement and placebo usîrs during
tbe second half of the sttid). Apparendy, the supplement pronioted significant weight loss during ihe first
8 weeks, after which its influence diminished. Although the actual cause is
unknown, it is possible that subjects
adapted physiologically to tlie supplement, becoming less sensiti"e to its
ingredients, making it less effective
over time.
According to the findings, one-onone coaching over the telep hone also
resulted in significant weight and body
fat losses in men and women. However,
unlike the effects of the supplement,
weight loss due to coaching was less
front-loaded and more bala iced over
the endre investigadon. In ihort,
coaching helped subjects lo ;e weigbt
and fat over tbe 4-month study, but it
did not have a significant eflect during
the first 8 weeks like the supplement
did.
Numerotis investigations f ave shown
that health coaching works.'""''^ Research has indicated that the coaching
strategy has helped type 2 d abedcs,"
increased fitness pardcipadc n,'''' supported lifestyle changes,'^•'^ improved
diet and food choices,'''' ma aged
stress,'^'' enhanced mental health,''''^ and
lowered health care costs.''' Although
rare, telephone coaching has also been
used in one case to improve diabetes
care.™ However, to date, few, if any,
invesdgations have studied the extent
to which coaching over the telephone
is a worthwhile weight-loss strategy.
Because cell phone use has become
commonplace, allowing the ovei"weight
to communicate with weight-loss coaches in almost any setdng, and because
we live in a fast-paced society, limidng
time to meet with health professionals,
telephone coaching designed to help
with weight loss seems to be a commonsense soludon. Obese individuals
who need assistance losing weight btit
feel too busy or too shy to meet one on
one may be able to find dme to work
with a weight-loss coach over the
telephone. Less time and less travel are
required compared with attending
meetings and personal visits, making
telephone coaching valuable to many
adults.
In tbe present study, tbe stipplement
and coaching were effective in producing significant weight loss in men
and women. However, the two strategies worked better in combination
than individually, displaying an additive effect. Specifically, adults who took
the supplement and received coaching
lost almost twice the weight and body
fat compared with those who took the
supplement btit received no coaching
or those who received coaching but
took tbe placebo. In short, the two
weight-loss strategies, supplement use
and telephone coaching, best promote
weigbt loss when used together.
Although there are several possibilities, the positive combined effects of
the supplement and coaching may be
pardy a funcdon of the dme-course
benefits of each treatment. The supplement had its greatest impact early in
the study, likely ctirbing appedte while
new behaviors were being adopted.
Later, as the effect of the supplement
diminished, behavior changes restilting from coaching condnued to help
with additional weight and fat los.ses.
Using the intent-to-treat approach
for the data analyses weakened the
effects of the treatments, especially lor
telephone coaching. Using the intentto-treat strategy, eveiy stibject who
began the study was included in the
analyses, even those who dropped out
and those who did not comply with the
assigned protocol. Although this approach is commonly tised to protect
against biases tbat may lestilt from
dropouts and noncompliance, the intent-to-tieat method may not be a good
analysis strategy given the purpose of
the present study. Combining subjects
who should have taken the stipplement
but did not with those who took the
stipplement and combining stibjects
wbo should have received telephone
coaching but did not with those who
pardcipated in the coaching inteiA'endon may introduce more bias into tbe
study than it prevents.
In this study, the goal was to determine the direct effect of the supplement and telephone coaching on
weight loss. It is doubtful tbat tbe effect
of tbese treatments can be determined
if subjects who did not receive the
treatment, whether because of qtiitdng
the sttidy or not complying, are combined with subjects who received the
treatment. True, the effect of a program.
November/December 2008, Vol. 23, No. 2
127
designed to use these treatments can
be evaluated using the intent-to-treat
approach, but it is unlikely that the
direct effect of the supplement and
coaching interventions can be measured using this strategy. The intent-totreat approach was included for those
who favor this method of analysis.
Strengths of the present study included a large sample size, random
assignment of subjects to groups, equal
number of male and female pardcipants, low dropout rate, use of a placebo and double-blind strategy for the
supplement, body fat changes measured using DEXA, and three assessment periods over the duration of the
investigadon. Weaknesses included little ethnic diversity and a 4-month study
duration.
CONCLUSION
Approximately two in every three
American adults are overweight or
SO WHAT? Implications for Health
Promotion Practitioners and
Researchers
The present study indicated that
regular weight-loss coaching over
the telephone can be used to help
overweight and obese adults lose
significant amounts of weight and
body fat. Given the prevalence of
obesity in the workplace, telephonebased weight-loss coaching may allow obese employees to work with
weight-loss coaches without having
to leave work or travel. Also, given
the number of adults who carry cell
phones, this weight-loss strategy may
encourage greater contact between
individuals striving to lose weight
and weight-loss coaches. The current investigation also showed that
a weight-loss supplement can be
used to jump-start the weight-loss
process and facilitate reductions in
body weigbt and fat in overweight
and obese adults. Together, the two
intervendons may be useful in
helping to curb the costly and
growing problem of obesity. Future
research is needed to identify other
strategies that can be employed to
assist individuals who have limited
time but need help in fighting
obesity.
128
American Journal of Health Promotion
obese. The cost associated with overweight and obesity in the workplace is
substantial. Although there are a variety
of programs that can be employed to
assist with weight loss, many have not
been studied using sound research
methodologies. The two weight-loss
treatments evaluated in the present
study, a weight-loss supplement and
diet and exercise coaching via telephone, appear to be effective weightloss interventions. When used separately, their benefits are significant.
When used in combination, their
weight-loss effects double.
Acknowledgments
Wi thank the partidpants of this study for their cooperation.
This study xuas funded by a research grant from TriVita,
Inc.
References
1. Ogden CL, Carroll MD, Curtiti LR, et al.
Prevalence of overweight and obesity in
the United States, ^999-2004. JAMA.
2006;295;1549-1555.
2. Hoffmans MD, Krotnhotir D, DeLezenne
Coulander C. The impact of body mass
index of 78,612 18-year old Dutch men on
32-year mortality from all causes. / Ctin
Epidemiol 1988;41:749-756.
3. Manson JE, Willett WC, Stampfer MJ, et al.
Body weight and mortality among women.
N Engt f Med. 1995;3S3:677-685.
4. Expert Panel on the Identification,
Evaluation, and Treatment of Overweight
and Obesity in Adults, Clinical guidelines
on the identification, evaluation, and
treatment of overweight and obesity in
adults. AmJ Clin Nutr. 1998;68:899-9n.
5. Lee I-M, Manson JE, Hennekens CH,
Paffenbarger RS. Body weight and
mortality: a 27-year follow-up of middleaged men. JAMA. 1993;270:2823-2828.
6. Larsson B, Bjorntorp P, Tibblin G. The
health consequences of moderate obesity.
IntJObes. 1981;5:97-116.
7. Finkelstein E, Fiebelkorn C, Wang G. The
costs of obesity among ftill-time employees.
AmJ Health Promot. 2005;20:45-51.
8. Gorsky RD, Pamuk E, Williamson DF,
Shaffer PA, Koplan JP. The 25-year health
care costs of women who remain
overweight after 40 years of age. AmJ Preo
Med. ]996;12:388-394.
9. Schmier JK, Jones ML, Halpern MT. Cost
of obesity in the workplace. ScandJ Work
Environ Health. 2006;32:5-ll.
10. Tucker LA, Friedman GM. Obesity and
absenteeism: an epidemiologic study of
10,825 employed adults. AmJ Health
Promot. 1998;12:202-207.
11. Tucker LA, Clegg AG. Differences in
health care costs and titilization among
adults with selected lifestyle-related risk
factors. AmJ Health Promot.
2002;16:225-233.
12. CarrowJS, Summerbell CD. Meta-analysis:
effect of exercise, with or without dieting.
on the body composition of ovenveight
subjects. EurJ Ctin Nutr. 1995;49:l-10.
13. Miller WC, Koceja DM, Hamilton EJ. A
meta-analysis of the past 25 years of weight
loss research tising diet, exercise, or diet
plus exercise intei^vention. intJ Obes.
1997;21:941-947.
14. Perri MG, Fuller PR. Success and failtire in
the treatment of obesity: where do we go
from here? Med Exerc Nutr Health.
1995;4:255-282.
15. National Heart, Lung, and Blood Instittite,
Clinical guidelines on the identification,
evaltiation, and treatment of ovei'weight
and obesity in adults: the evidence report.
Obes Fies. 1998;6(suppl 2):51S-209S.
16. Klein ML, Wing RR, McGuiie MT, Seagle
HM, Hill JO. A descriptive study of
individuals sticcessftil at long-term
maintenance of stibstantial weight loss.
AmJ Clin Nutr. 1997;66:239-246.
17. Mcguire MT, Wing RR, Klem ML, Lang W,
Hill JO. What predicts weight regain
among a grotip of sticcessful weight losers?
J Consult Clin Psychol. 1999;67:177-185.
18. Wing RR. Behavioral approaches to the
treatment of obesity. In: Bray GA,
Bouchard G, James WPT, eds. Handbook of
Obesity. New York, NY: Marcel Dekker Inc;
1998:855-873.
19. Nachtigal MC, Patterson RE, Stiatton KL,
et al. Dietary supplements and weight
control in a middle-age population.//I/ÍÍTTO
Complement Med. 2005; 11:909-915.
20. Pittler MH, Ernst E. Dietary supplemenLs
for body-weight redtiction: a systematic
review. AmJ Clin Nutr. 2004;79:529-536.
21. LeCheminantJ, Tucker L, Peterson T,
Bailey B. Differences in body fat
percentage measured using dtial energy xlay absorptiometry and the Bod Pod in 100
women. Med Sei Sports Exerc. 2001;33:S174.
22. Bailey B, Tucker L, Peterson T,
LeCheminantJ. Test-retest reliability of
body fat percentage results using dual
energy x-ray absorptiometry and the Bod
Pod. Med Sd Sports Exerc. 2001;33:S174.
23. Downs BW, Bagchi M, Subbai aju GV, et al.
Bioefficacy of a novel calcium-potassitim
salt of (-)-hydroxycitric acid. Mutat lies.
2005;579:149-162.
24. Kim MS, KiniJK, Kwon DY, Park R. Antiadipogenic effects of Garcinia extract on
the lipid droplet, acctimtilation and the
expression of transcription factor.
Biofactors. 2004;22:193-196.
25. Kimura I. Medical benefits of tising natural
compounds and their derivatives having
multiple pharmacological actions.
Yakugaku Zasshi 2006;l26:133-143.
26. Monograph: Gymnema sylvestre. Altem
Med Rev. 1999;4:46-47.
27. Chaturvedi P. Role of Momoidica
charantia in maintaining the normal levels
of lipids and glucose in diabetic rats fed
a high-fat and low-carbohydrate diet.
BrJBiomedSd. 2005;62:124-126.
28. Chen Q, Li ET. Reduced adiposity in bitter
melon (Momordica charantia) fed rats is
associated with lower tissue triglycéride
and higher plasma catecholamines.
BrJNutr. 2005;93:747-754.
29. Kim SH, Hyun SH, Choung SY Antidiabetic effect of cinnamon f xtract on
blood glticose in d b / d b mice.
J Ethnopharmacol. 2006; 104:11
30. Ooi VE, Liti F. Immtinomodulation and
anti-cancer activity of polysac ;harideprotein complexes. Curr Med Chem.
2000;7:715-729.
31. Jia W, Gao W, Tang L. Anti-diabetic herbal
drtigs officially approved in C hina.
Phytotherapy Res. 2003;17:1127-1134.
82. Diepvens K, Westerterp KR, ^VesterterpPlantenga MS. Obesity and tliermogenesis
related to the consumption c f caffeine.
ephedrine, capsaicin and gre
AmJ Physiol Regul Integr CompPhysiol.
2007;292:R77-R85.
33. Westerterp-Plantenga MS, Le etine MP,
Kovacs EM. Body weight loss and weight
maintenance in relation to h ibittial
caffeine intake and green tee
stipplementation. Obes Res.
2005;13:1195-1204.
34. Wang H, Reaves LA, Edens ^ K. Ginseng
extract inhibits lipolysis in rat adipocytes in
vitro by activating phosphodi îsterase 4.
f Nutr. 2004;l.36:337-342.
35. Monograph: I.-Theanine. Altem Med Rev.
2005; 10:136-138.
36. Targonsky ED, Dai F, Koshkiji V, et al.
Alpha-lipoic acid regtilates Al »IP-activated
protein kiiiase and inhibits ii stilin
.secretion from beta cells. Die beiologia.
2006;49:1587-1598.
37. Lips P. Vitamin D physiology Prog Biophys
Mol Biol. 2006;92:4-8.
38. Zemel MB. The role of dairy foods in
weight management, y/im Ci II Nutr.
2005;24(suppl 6):537S-546S.
39. YbarraJ, Sanchez-Hernandez J, Gich 1, et
al. Unchanged hypovitamino lis D and
secondaiy hyperparathyroidism in morbid
obesity after bariatric stirgery. Obes Surg.
2005;l 5:330-335.
40. Chen G, Liu P, Pattar GR, et al. Chromium
activates glucose transporter 4 trafficking
and enhances insulin-stimulated glucose
transport in 3T3-L1 adipocytes via
a cholesterol-dependent mechanism. Mol
Endoainol. 2006;20:857-870.
41. Pitder MH, Stevinson C, Ernst E.
Chromium picolinate for reducing body
weight: meta-analysis of randomized trials.
Intf Obes Relat Metab Disord.
2003;27:522-529.
42. KeithleyJ, Swanson B. Glucomannan and
obesity: a critical review. Altem Ther Health
Med. 2005;l 1:30-33.
43. Birketvedt GS, Shimshi M, Erling T,
Florholmen J. Experiences with three
different fiber stipplements in weight
redtiction. Med Sa Monit. 2005;l 1:5-8.
44. Vita PM, Restelli A, Caspani P, Klinger R.
Chronic tise of glucomannan in the dietary
treatment of severe obesity. Minerva Med.
1992;83:135-139.
45. Walsh DE, Yaghoubian V, Behforooz A.
Effect of glucomannan on obese patients:
a clinical study, ¡ntj Obes. 1984;8:289-293.
46. WellCoaches: Helping Physical and Mental
Health Professionals Become Great
Coaches. Available at: http://www.
wellcoach.com. Accessed May 15, 2007.
47. American College of Sports Medicine
(ACSM) Expert Panel, Position stand:
appropriate intervention strategies for
weight loss and prevention of weight
regain for adults. Med Sd Sports Exerc.
2001;33:2145-2156.
48. Kroke A, Liese AD, Schultz M, et al. Recent
weight changes and weight cycling as
predictors of stibsequent two year weight
change in a middle-aged cohort. Intf Obes
Relat Metab Disord. 2002;26:403-409.
49. Wong ML, Koh D, Lee MH, Fong YT. Twoyear follow-up of a behavioral weight
control programme for adolescents in
Singapore: predictors of long-term weight
loss. Ann Acad Med Singapore.
1997;26:147-153.
50. Yoting D, Ftirler J, Vale M, et al. Patient
engagement and coaching for health: the
PEACH sttidy: a eltister randomized
controlled trial using the telephone to
coach people with type 2 diabetes to
engage with their GPs to improve diabetes
care. BMC Fam Pract. 2007;ll:20.
51. Butcher L. Modest investment in
'coaching' seems to lead to lowered costs.
Manag Care. 2006;15:68-69.
52. Buttei-worth S, Linden A, McClay W, Leo
MC. Effect of motivational interviewingbased health coaching on employees'
physical and mental health stattis. y Ocaip
Health PsychoL 2006;(4):358-365.
53. Hawksley B. Work-related stress, worklife
balance and personal life coaching.
BrJ Community Nurs. 2007;]2:34-36.
54. Lipscomb R. Health coaching: a new
opportunity for diabetes professionals.y/\m
DietAssoc. 2006; 106:801-803.
55. Huffman M. Health coaching: a new and
exciting techniqtie to enhance patient selfmanagement and improve otitcomes.
Home Healthc Nurse. 2007;25:27]-274.
56. Tidwell L, Holland SK, CreenbergJ, et al.
Commtmity-based ntirse health coaching
and its effect on fitness participation.
Uppincotts Case Manag 2004;9:267-279.
57. Whittemore R, Melkus CD, Sullivan A,
Grey M. A nurse-coaching intervention for
women with type 2 diabetes. Diabetes Educ.
2004;30(5):795-804.
November/December 2008, Vol. 23, No. 2
129