T YPE OF C ARBOHYDRATES FOR P REVENTION OF W EIGHT G AIN
9.6.2 T YPE OF C ARBOHYDRATES FOR P REVENTION OF W EIGHT G AIN
Five prevention trials among adults were identified that resulted in a significant increase in dietary fiber intake relative to controls. 129–132,136 Two 129,131 detected a decrease in weight or BMI relative to controls. The others found no significant impact. However, only two aimed to increase fiber intake per se, 129,130 one of which favorably impacted weight. Another aimed to increase complex carbohydrates 131 and also favorably impacted weight. Both the trial that aimed only to increase fruit and vegetable intake 132 and the trial that only targeted a decrease in dietary fat 136 failed to significantly impact weight relative to controls. It is difficult to draw conclusions
Carboh
TABLE 9.3 Prevention Trials among Adults That Targeted or Impacted Carbohydrate Intake (in Descending Order by Sample Size)
ydrates and Obesity
Results: Impact on Measure of
Length of
Relevant Target Behaviors
Adiposity
Author, Year
Intervention
Direction of
Study Study Population,
and Timing of
Change
Control Location
Name Sample Size, Age,
Study Design and
Follow-Up
Relative to
Reported Change
Control Group
Variables Comments
Gender No significant Polyp
Lanza, 2001 2079 adults with large- Randomized
4 years
↓ Dietary fat ↓ Dietary fat (% and g/day)
differences at Prevention
bowel adenomatous
controlled trial;
↑ Intake of fruits
↑ Intake of fruits and
(Weight)
baseline between Trial
polyps, 35–89 years
individualized
and vegetables
vegetables (servings/MJ
groups for gender, U.S.
old,
instruction and
↑ Dietary fiber
and g/day)
88–91% white
counseling
↑ Fiber (g/MJ)
age, minority race,
program to prevent
0 Change in total calories
education, marital
the recurrence of
↑ Carbohydrates (%)
status, BMI, current
adenomatous
↑ Protein (%; men)
smoking, current
polyps
↑ Calcium (men),
aspirin use, or
↑ Whole grains (g/day)
vigorous and
↓ High-fat foods (g/day;
moderate physical
red/processed meats,
activity
high-fat dairy and desserts)
↑ Low-fat alternatives (g/day)
Carboh
0 Age, stage of No significant Women’s
Rock, 2001 1010 women,
Randomized
1 year
↑ Fruit and
↑ Fruit and vegetable intake
cancer at differences in age, Healthy
18–70 years old, 86%
controlled trial;
vegetable intake
(servings/1000 kcal)
(Weight)
ethnicity, education Eating and
non-Hispanic white
individualized
↑ Fiber intake
↑ Fiber intake (g/1000 kcal)
initial
ydrates and Obesity
dietary
↓ Percentage of
↓ Percentage of calories
diagnosis, level, stage at
overweight diagnosis, or BMI (WHEL)
Living
counseling; tested
calories from
from dietary fat
between intervention Study
effect of low-fat,
dietary fat
↑ Percentage of calories
status,
menopausal and comparison California,
high-vegetable
from carbohydrates
groups at baseline Arizona,
diet on patients at
status
*Change in vegetable Texas, and
risk for breast
intake was inversely Oregon
cancer recurrence
associated with weight change
Bhargava, 926 postmenopausal
Baseline values were 2002
Randomized control
1 year
↓ Energy intakes
↓ Fat intake (g) (saturated
similar across groups. Women’s
women, 50–70 years
trial; group dietary
from fat to ~20%
fat, monounsaturated fat,
(Weight)
*In both intervention Health
old, 28% black, 16%
counseling; weight
calories
and polyunsaturated fat)
and control groups, Trial:
Hispanic, 54% white
gain prevention
↓ Intake of
↓ Energy intake
(Waist
weight change was Feasibility
intervention
saturated fat
↑ % total calories from
circumference)
explained by changes Study in
↑ Consumption of
carbohydrates
in carbohydrate and Minority
fruits, grain
(Hip
saturated, Populations
products, and
circumference)
monounsaturated, Georgia,
vegetables
and polyunsaturated Alabama,
fats and Florida
TABLE 9.3 (continued)
352 Prevention Trials among Adults That Targeted or Impacted Carbohydrate Intake (in Descending Order by Sample Size)
Length of
Author, Year
Intervention
Study Study Population,
and Timing of
Results:
Impact on Measure of Location
Name Sample Size, Age, Study Design and
Relevant Target Behaviors
Adiposity
Comments
Boyd, 1997 786 women with
Baseline Canadian
Randomized
2 years
↓ Intake of dietary ↓ Mean percentage of
characteristics were Diet and
mammographic
controlled trial;
fat to 15% of total
calories derived from fat
(Weight)
similar across Breast
(fell from 33 to 21%)
(intervention and Cancer
aged 30–65 years,
individual dietary
↑ Intake of
Protein intake as a percent
control) groups Prevention
race/ethnicity not
counseling to
complex
of total calories was
specified
determine whether
carbohydrates
unchanged
Study Group
adoption of low-
↑ Carbohydrate intake
Toronto,
fat, high-
(rose from 50 to 61% of
Hamilton,
carbohydrate diet
calories)
London, and
would reduce the
↑ Intake of total dietary
Windsor in
area of
fiber (from 17.2 to 20.3
Ontario
radiologically
g/day)
dense breast tissue
Functional F
Smith- 201 adults with
↑Intake of 0 Baseline No significant Warner,
Randomized
1 year
↑ Intake of fruits
value, gender differences at 2000
adenomatous large-
controlled trial;
and vegetables
fruits/vegetables
(Weight)
baseline between Minnesota
0 groups for age, Cancer
bowel polyps, 30–74
individual diet
(servings/day)
years old, 99% white
counseling to
0 Change energy intake or
prevent colon
protein (%)
(BMI)
gender, household
ood Carboh
income, education, Research
Prevention
cancer
↓ Dietary fat (%)
marital status, Unit
↑ Carbohydrate (%)
employment, Intervention
↑ Fiber (g/day)
ethnicity, smoking, Study
BMI, alcohol intake, Minneapolis,
ydrates
or use of nutrient
MN supplements
Carboh
0 No significant Reading and
Cox, 1998 125 adults, 16–65 years Randomized
8 weeks
↑ Intake of fruits
↑ Intake of fruits and
differences at Glasgow,
old
controlled trial;
and vegetables
vegetables (g/day;
(Weight)
baseline between U.K.
education to
attenuated but remained
(Both
ydrates and Obesity
promote fruit and
after 1-year follow-up)
groups for age,
vegetable
0 Difference in calories
intervention and
gender, occupation,
consumption
↓ (in both intervention
control groups
household income,
and control groups), fat
gained weight)
employment status, or (%; except significant ↓ BMI
in subgroup with baseline fat of >35%), or starch (%)
↑ CHO (%) and total sugars (%)
Simon, 1997 133 women at high risk Randomized
0 Study site No p values were Detroit, MI,
3 months of
↓ Dietary fat intake ↓ Mean percent caloric
reported for dietary and Wichita,
for developing breast
Controlled trial;
intensive
to 15% of total
intake from fat (from 36 to (Weight and
changes but they KS
cancer,
combination of
intervention, 12
calories
18%); this change was
percent body fat)
aged 18–67 years, 89%
appeared to be Caucasian, 9% African
education, goal
months follow-
maintained at 12 months
significant; women in American, 2%
setting, evaluation,
up
↓ Mean caloric intake at 12
the low-fat diet group Hispanic
feedback, and
measurements
months compared to
participant self-
baseline
lost an average of 3 lb
monitoring,
↑ Dietary fiber intake at 3
and women in the
included both
months; increase was
nonintervention
intensive
maintained at 12 months
group lost an average
individual
of 5 lb; % body fat ↓
counseling
slightly for both
sessions and group
groups
meetings; weight reduction was not encouraged
354 TABLE 9.4
Prevention Trials among Children That Targeted or Impacted Carbohydrate Intake (in Descending Order by Sample Size)
Relevant Targeted Behaviors
Results:
Length of
Impact on Measure of Adiposity
Intervention
Direction of
Author, Year Study Population,
and Timing
Change
Study Name Sample Size, Age,
Study Design
of Follow-
Relative to
Location Ethnicity
and Strategies Up Measure
Targeted
Reported Change
Control Group Control Variables Comments
No significant Child and
Luepker, 1996 5106 children (school- Randomized
3 school years ↓ Dietary fat
School level:
0 School level:
Observation days differences at Adolescent Trial
level data), 4019
controlled trial;
↑ Physical activity
↓ Fat (%) in school
(BMI)
0 within semester baseline between for
children (individual-
school-based
lunch menus
and lessons within groups at school- Cardiovascular
level data), grades
multicomponent
↓ Dietary energy in
(TSF or SSF)
observation days, level for Health
3–5, 69% white, 13%
CVD risk
school lunch menus
location of the environmental, (CATCH)
African American,
reduction
↑ Physical activity
lesson, specialty of behavioral, San Diego,
14% Hispanic
program
intensity in PE
psychosocial, and Houston, New
(education, PE,
Individual level:
the teacher
school lunch, and
↓ Rise in dietary energy
Functional F
Individual level: risk factor data
Baseline value, Not explicitly stated Minneapolis
Orleans, and
home programs
(MJ/d)
for half of the
↓ Dietary fat (%)
gender, ethnicity, in paper, but
families)
↑ CHO intake (%)
CATCH field site, prevention of
0 Change in protein
random effect of obesity was not a
intake (%)
school with site goal of CATCH, but
ood Carboh
↑ vigorous physical
and intervention rather, it aimed to
activity
group
avoid growth retardation
ydrates
Carboh
0 Age, site, gender, Not explicitly stated CATCH
Nader, 1999 3714 children, grades
Randomized
3-year follow- ↓ Dietary fat
↓ Dietary fat (%)
ethnicity, intraclass in paper, but San Diego,
controlled trial;
up (after 3-
↑ Physical activity
↑ CHO (%)
(BMI)
0 correlation within prevention of Houston, New
(73% of original
school-based
year
0 Change protein (%)
ydrates and Obesity
↑ Vigorous physical
(TSF or SSF)
school and among obesity was not a
students, gender × goal of CATCH, but Minneapolis
Orleans, and
CVD risk
activity
reduction
↓ (Note: dietary energy
ethnicity
rather, it aimed to
program
at end of 3-year
interaction
avoid growth
(education, PE,
intervention gone by
retardation
school lunch, and
3-year follow-up)
home programs for half of the families)
The Writing 663 children with
0 Gender, baseline No significant Group for the
Randomized
3 years
↓ Dietary fat
↓ Total fat (%)
differences at DISC
elevated LDL
controlled trial;
energy and other
↓ Total energy (kJ/d)
(BMI)
value
0 baseline between Collaborative
cholesterol,
clinic-based,
nutrients at RDA
↑ Protein (%)
groups for age, Research Group,
0 gender(?) (appears 1995
race/ethnicity not
family-oriented
0 Change in diet, Ca,
so, but not explicitly The Dietary
specified
dietary
Zn, Fe, vitamins A and
counseling
(Sum TSF, SSF,
stated),
Intervention
anthropometry, Study in
program to
0 Change in serum
and suprailiac
0 and blood pressure; Baltimore, MD,
blood lipid levels, Children
reduce LDL
ferritin, Zn, retinol
skinfold)
cholesterol
small differences in Chicago, IL,
(WHR)
dietary intake, with Iowa City, IA,
intervention group Newark, NJ,
having slightly New Orleans,
lower % energy LA, and
from PUFA and Portland, OR
slightly higher intakes of vitamin B 6 and Zn Intervention group had a slightly higher proportion with
household income <$20K
TABLE 9.4 (continued)
Prevention Trials among Children That Targeted or Impacted Carbohydrate Intake (in Descending Order by Sample Size)
Length of Intervention
Author, Year Study Population,
and Timing
Study Name Sample Size, Age,
Study Design
of Follow-
Relevant Targeted Behaviors
Results:
Location Ethnicity
and Strategies Up Measure
Impact on Measure of Adiposity Comments
0 Age, ethnicity, At baseline, Know Your Body,
Resnicow, 1992 1209 children, 6–13
Nonrandomized
1 1 / 2 -year
↑ Health knowledge
0 Significant
gender, baseline intervention students comprehensive
years old,
control trial;
intervention
↑ Fiber content of
differences in dietary
(BMI)
did not significantly school health
foods served in
indices
values
Hispanic population
comprehensive
3-year follow-
school
↑ Health knowledge at
differ with regard to
sex, total program
education school health
up measure
↓ Fat content of
3-year follow-up
cholesterol, systolic New York
education
foods served in
↑ Number of servings
program
school
of vegetables and
blood pressure,
(classroom
↑ Vegetable and
heart-healthy foods
BMI, health
curriculum,
heart-healthy
↓ Number of servings
attitudes, and self-
schoolwide
indices
of meat and desserts
efficacy; they were
health activities,
significantly
and
younger, more likely
Functional F
environmental
to be Hispanic, and
modifications)
had significantly lower health
knowledge and fruit intake scores than control students
ood Carboh
ydrates
Vandongen, 1995 869 children, 10–12
Gender, baseline West Australia
Randomized
9 months
↑ Consumption of
↓ % Total energy from
years old, considered
controlled trial;
fruit, vegetables,
sugar (boys only)
to be representative
school-based
whole-grain bread
↓ % Total energy from
skinfolds, boys
sample of the
nutrition and
and cereal relative
fat (girls only)
and girls)
socioeconomic mix of
fitness program
to other foods
↓ % Total energy from
the community in
to improve
↓ Consumption of
saturated fat (girls
(Subscapular
ydrates and Obesity
West Australia,
cardiovascular
fatty, sugary, and
only)
skinfolds,
race/ethnicity not
risk factors
salty foods relative
0 Change in total
boys and girls)
specified
to other foods
energy (boys and
girls) ↑ % Total energy from (% Body fat,
boys and girls)
protein (boys only) ↑ Fiber intake, g/day
(boys and girls)
(BMI, boys and girls)
Burke, 1998 720 children,
0 Gender, baseline At baseline, there Western Australia
Randomized
20-week (2
↑ Duration and
↑ Physical fitness (boys
were no significant race/ethnicity not
11 years old,
controlled trial;
school
frequency of
and girls)
(BMI, boys and
values
differences in specified
school- and
terms)
physical activity
0 Change in physical
↓ Consumption of
activity (boys and
dietary variables,
physical
and 6-month
fat, sugar, and salt
girls)
(Subscapular
time spent in leisure-
enrichment
follow-up
↑ Fiber intake
↓ TV watching (boys
skinfolds, girls
time physical
program for
activity, or hours of
children at
0 Dietary change (boys
TV watching
higher risk of
and girls)
(Triceps
cardiovascular
skinfolds, boys
disease
and girls)
Donnelly, 1996 44 subjects, 64 controls,
Nonrandomized
2 school years ↓ Intake of fat
0 Significant change in
0 Schools were
Rural Nebraska grades 3–5, subsample
controlled trial;
↓ Intake of
total energy, % kcal
(Weight, BMI,
matched for
of 11 subjects and
ethnicity/SES and 25 controls with 22%
school-based
cholesterol
from fats,
and body fat %
multicomponent
↓ Intake of sodium
body fat,
characteristics race/ethnicity not
program
↑ Intake of fiber
proteins, or fiber
weighing)
0 (grade, height, specified
(nutrition
↑ Physical fitness
↓ Intake of sodium
education,
and knowledge and
(Attenuation of
weight, BMI, mile-
modified school
awareness of diet in
obesity —
run time)
lunches, and
health
subjects with
enhanced
body fat of
physical activity
program)
TABLE 9.4 (continued)
Prevention Trials among Children That Targeted or Impacted Carbohydrate Intake (in Descending Order by Sample Size)
Length of Intervention
Author, Year Study Population,
and Timing
Study Name Sample Size, Age,
Study Design
of Follow-
Relevant Targeted Behaviors
Results:
Location Ethnicity
and Strategies Up Measure
Impact on Measure of Adiposity Comments
Sahota, 2001 203–303 children, 8–10
No significant Active
Randomized
12 months
Influence of diet and
↑ Vegetable intake
0 Gender, age,
baseline BMI differences were Programme
years old, some ethnic
controlled trial;
physical activity
↓ Fruit intake in obese
(BMI)
found between the Promoting
minority children in
intervention and Lifestyle in
sample
multidisciplinar
↑ Consumption of
↑ Intake of foods and
comparison pupils Schools
y intervention to
fruits and
drinks high in sugar in
for any of the (APPLES)
reduce risk
vegetables
overweight children
measures at baseline Leeds, U.K.
factors for
↓ Consumption of
↑ Sedentary behavior in
obesity
foods high in fat
the overweight
↓ Consumption of
children
foods and drinks high in sugars
Functional F
ood Carboh
ydrates
Carboh
0 No significant Childhood Weight
Epstein, 2001 27 intervention families
Randomized
6-month
↑ Fruit and vegetable
↑ Fruit and vegetable
differences at Control and
(at least 1 obese (BMI
intake (servings/day)
(Percentage of
baseline between Prevention
> 85th percentile)
trial; parent-
and
↓ High-fat and high- ↓ High-fat and high-
overweight)
ydrates and Obesity
parent + a nonobese
focused
1-year follow-
sugar food intake
sugar foods
groups for gender,
age, weight, % Buffalo, NY
Program (BMI < 85th
behavioral
up measure
(servings/day)
percentile) child, 6–11
overweight, family years old)
intervention on
parent and child
history of obesity
eating changes,
and chronic diseases
and weight
(except for more
control
HTN in families in
treatment for
fat/sugar group),
parents
food habits, child feeding practices, and confidence in making choices Correlations showed no differences by age or gender in outcomes
Functional Food Carbohydrates
regarding the independent impact of dietary fiber on adiposity given the limited number of studies and the variability in the combination of target behaviors in each
intervention. However, it appears that dietary fiber is sometimes, but not always, effective in preventing weight gain. Interventions may be more effective when they
explicitly target fiber intake from a variety of sources, including whole grains. Four programs specifically targeted an increase in fiber intake among chil- dren. 137–140 Only one, however, measured and detected an increase in fiber intake among subjects compared to controls. 138 Therefore, once again it is hard to arrive at a conclusion regarding the impact of a reduction in fiber intake, when most of the studies were unable to produce a detectable change. Although half of these four studies did observe an impact on adiposity, 138,139 this impact was observed only with regard to skinfolds, and not BMI. All of these programs aimed to reduce fat or sugar as well as increase fiber, and two of them also targeted physical activity, 139,140 again making it difficult to attribute program impact (or lack thereof) to any specific targeted behavior. We can conclude only that increases in fiber intake may be part of an effective strategy to prevent overweight in children.
Only one study examined sugar intake among adults. 133 This study, which aimed to increase fruit and vegetable intake, resulted in an increase in total sugar intake and did not have a significant impact on weight of subjects relative to controls. Based on this limited data, no conclusions can be drawn regarding sugar intake among adults for the prevention of weight gain.
Four studies were identified that specifically targeted the reduction of sugar or foods high in sugar among children. 125,138,139,141 Three of these were school-based
randomized controlled trials, and the other 125 was a family-focused behavior inter- vention that did not include a control group. The only study that detected a decrease in the intake of high-sugar foods did not observe an impact on adiposity. 125 Another study 141 actually detected an increase in the intake of high-sugar foods and beverages relative to controls and observed no impact on BMI. Although half of these trials demonstrated an impact on adiposity (in regard to skinfolds, but not BMI), all of these interventions targeted multiple dietary changes, and some also aimed to alter physical activity, making it impossible to determine the independent effect of sugar intake on adiposity. It appears that a reduction in sugar intake can be part of an effective strategy to prevent increases in adiposity, but interventions reported to date have been largely ineffective in reducing sugar intake.