Weight Loss: Glycemic Load

[Guest guest]

The below may be of interest:

Weight Loss: Glycemic Load Had No Significant Effect

http://www.sciencedaily.com/releases/2007/04/070409082419.htm

Science Daily — The first phase of a caloric restriction study in

human subjects at the Mayer US Department of Agriculture Human

Nutrition Research Center on Aging (USDA HNRCA) at Tufts University

found evidence suggesting that calorie-restricted diets differing

substantially in glycemic load can result in comparable long-term

weight loss.

the study, part of the multi-center Comprehensive Assessment of Long-

term Effects of Restricting Intake of Energy (CALERIE) trial, funded

by the National Institute on Aging, accounted for dietary factors

that affect hunger and satiety, used laboratory techniques to measure

adherence, and was the first of its kind to provide a complete set of

meals and snacks to its participants. Recruitment is currently

underway for participation in the second phase of the CALERIE study

at Tufts, which will examine the relationship between calorie-

restricted diets, aging, and age-related disease.

" Participants in our pilot study achieved and maintained comparable

weight loss after one year, regardless of whether they were on a low-

glycemic-load or a high-glycemic-load diet, " says corresponding

author , PhD, director of the USDA HNRCA's Energy

Metabolism Laboratory. " The goal was for both groups to restrict

calories by 30 percent and, after one year, both groups had lost an

average of 8 percent of their original body weight. We found that the

two groups did not differ significantly in their average body fat

loss, energy intake, metabolic rate, or reports of hunger and

satiety. "

The two study diets were carefully matched for factors known to

influence food intake during weight-loss efforts, such as

palatability, dietary variety, and fiber. " Because there was careful

attention to factors that influence hunger and satiety, participants

were generally satisfied on a calorie-restricted diet, " says ,

who is also a professor at the Friedman School of Nutrition Science

and Policy at Tufts.

Thirty-four overweight but otherwise healthy men and women were

assigned randomly to a low-glycemic-load (LG) or high-glycemic-load

(HG) diet. At six months, the LG group had lost an average of 10.4

percent body weight, while the HG group had lost an average of 9

percent body weight. By 12 months, participants in both the LG and HG

groups had lost an average of 8 percent of their starting body weight.

" Unlike several other long-term studies, which have reported greater

weight loss with low GL diets at six months but no differences by 12

months, our data show no significant short-term or long-term

differences, " notes Sai Das, PhD, scientist at the USDA HNRCA and

first author of the study. " However, we did detect a greater tendency

for weight and body-fat regain among LG participants. This finding

suggests that reduced calorie intake may be harder to sustain on LG

diets over time. "

The LG diet contained 40 percent carbohydrate, 30 percent fat, and 30

percent protein; while the HG diet contained 60 percent carbohydrate,

20 percent fat, and 20 percent protein. A food's glycemic load is a

relative measure of how much carbohydrate is in the food and how

quickly that food is converted in the body to blood sugar. Examples

of foods provided as part of the LG diet include bean and barley

stew, low-fat cottage cheese, and pumpernickel bread. The HG diet

included foods like bagels, candied sweet potatoes and shepherd's pie

with mashed potatoes.

Both diets were designed to restrict calories by 30 percent, relative

to a person's baseline energy requirements, while providing the

recommended amounts of vitamins, minerals, and essential fatty acids.

All participants attended weekly behavioral support groups and met

individually with a dietitian.

To measure objectively actual dietary intakes, the researchers used a

laboratory technique involving doubly labeled water. They determined

that both groups ate more calories than study foods provided; at six

months the HG group averaged a 16 percent calorie-restricted diet and

the LG group averaged a 17 percent calorie-restricted diet. Although

participants did consume additional calories, the degree of non-

adherence was not significantly different between the LG and HG

groups when measured at various points throughout the study.

" An important difference between our study and other weight-loss

trials is that we did not rely on self-reported intakes, " says Das,

who is also an assistant professor at the Friedman

School. " Underreporting of caloric intake can vary between 5 and 50

percent. By providing the study food for the first six months, we did

not have to worry as much about lifestyle factors like shopping and

cooking habits interfering with dietary change. "

previously conducted a pilot study showing that a diet's

overall glycemic load may be an important determinant of weight loss

for people with high levels of insulin secretion, such as people with

diabetes. " We have observed that for some groups, glycemic load may

impact weight loss. However, in terms of calorie-restricted diets, we

see little difference among diets of varying glycemic load when we

account for factors that affect dietary adherence. "

This work was supported by a grant from the National Institute on

Aging, part of the National Institutes of Health; the USDA; and the

Boston Obesity Nutrition Research Center. For more information about

ongoing recruitment for the second phase of the CALERIE study at

Tufts, call , or visit

http://hnrc.tufts.edu/studies/2520.shtml.

================

Carruthers

Wakefield, UK

[Guest guest]

<<<<Weight Loss: Glycemic Load Had No Significant Effect

_http://www.sciencedhttp://wwhttp://wwhttp://www.scienhttp://w_

(http://www.sciencedaily.com/releases/2007/04/070409082419.htm)

Science Daily — The first phase of a caloric restriction study in

human subjects at the Mayer US Department of Agriculture Human

Nutrition Research Center on Aging (USDA HNRCA) at Tufts University

found evidence suggesting that calorie-restricted diets differing

substantially in glycemic load can result in comparable long-term

weight loss....

previously conducted a pilot study showing that a diet's

overall glycemic load may be an important determinant of weight loss

for people with high levels of insulin secretion, such as people with

diabetes. " We have observed that for some groups, glycemic load may

impact weight loss. However, in terms of calorie-restricted diets, we

see little difference among diets of varying glycemic load when we

account for factors that affect dietary adherence. " >>>

****

Interesting! I would love to have seen this study conducted with a third

group incorporating their personal choices of high/low glycemic loads (while

otherwise satisfying the dietary restrictions imposed by the study), but with

the addition of several rules on timing the participants' nutritional intake.

This would give some idea of how much impact adjustment of meal timing has on

weight loss compared to adjusting nutritional content alone.

kson, CMT, CST

Burnsville, MN USA

_www.cstminnesota.com_ (http://www.cstminnesota.com) <- under construction,

will be online in 1-2 weeks

" Better Living Through Movement. "

" Be good to yourself. If you don't take care of your body, where will you

live? "

- Kobi Yamada

[Guest guest]

Who else noticed what they missed in this study?

That't right, in this study they strickly focused on % of starting weight

reduction. While both groups lost about the same % of starting body weight, it

is entirely possible that the low glycemic group had better body compositional

changes - they may have lost more fat and kept more muscle. Now we'll never

know.

Besides changes in weight and body fat, it would have been great if they

included resting BMR, blood lipid profiles and blood pressure comparisions

before and after for both groups.

Ed White

Sandwich, MA USA

================

carruthersjam wrote:

The below may be of interest:

Weight Loss: Glycemic Load Had No Significant Effect

http://www.sciencedaily.com/releases/2007/04/070409082419.htm

Science Daily — The first phase of a caloric restriction study in

human subjects at the Mayer US Department of Agriculture Human

Nutrition Research Center on Aging (USDA HNRCA) at Tufts University

found evidence suggesting that calorie-restricted diets differing

substantially in glycemic load can result in comparable long-term

weight loss.

the study, part of the multi-center Comprehensive Assessment of Long-

term Effects of Restricting Intake of Energy (CALERIE) trial, funded

by the National Institute on Aging, accounted for dietary factors

that affect hunger and satiety, used laboratory techniques to measure

adherence, and was the first of its kind to provide a complete set of

meals and snacks to its participants. Recruitment is currently

underway for participation in the second phase of the CALERIE study

at Tufts, which will examine the relationship between calorie-

restricted diets, aging, and age-related disease.

" Participants in our pilot study achieved and maintained comparable

weight loss after one year, regardless of whether they were on a low-

glycemic-load or a high-glycemic-load diet, " says corresponding

author , PhD, director of the USDA HNRCA's Energy

Metabolism Laboratory. " The goal was for both groups to restrict

calories by 30 percent and, after one year, both groups had lost an

average of 8 percent of their original body weight. We found that the

two groups did not differ significantly in their average body fat

loss, energy intake, metabolic rate, or reports of hunger and

satiety. "

The two study diets were carefully matched for factors known to

influence food intake during weight-loss efforts, such as

palatability, dietary variety, and fiber. " Because there was careful

attention to factors that influence hunger and satiety, participants

were generally satisfied on a calorie-restricted diet, " says ,

who is also a professor at the Friedman School of Nutrition Science

and Policy at Tufts.

Thirty-four overweight but otherwise healthy men and women were

assigned randomly to a low-glycemic-load (LG) or high-glycemic-load

(HG) diet. At six months, the LG group had lost an average of 10.4

percent body weight, while the HG group had lost an average of 9

percent body weight. By 12 months, participants in both the LG and HG

groups had lost an average of 8 percent of their starting body weight.

" Unlike several other long-term studies, which have reported greater

weight loss with low GL diets at six months but no differences by 12

months, our data show no significant short-term or long-term

differences, " notes Sai Das, PhD, scientist at the USDA HNRCA and

first author of the study. " However, we did detect a greater tendency

for weight and body-fat regain among LG participants. This finding

suggests that reduced calorie intake may be harder to sustain on LG

diets over time. "

The LG diet contained 40 percent carbohydrate, 30 percent fat, and 30

percent protein; while the HG diet contained 60 percent carbohydrate,

20 percent fat, and 20 percent protein. A food's glycemic load is a

relative measure of how much carbohydrate is in the food and how

quickly that food is converted in the body to blood sugar. Examples

of foods provided as part of the LG diet include bean and barley

stew, low-fat cottage cheese, and pumpernickel bread. The HG diet

included foods like bagels, candied sweet potatoes and shepherd's pie

with mashed potatoes.

Both diets were designed to restrict calories by 30 percent, relative

to a person's baseline energy requirements, while providing the

recommended amounts of vitamins, minerals, and essential fatty acids.

All participants attended weekly behavioral support groups and met

individually with a dietitian.

To measure objectively actual dietary intakes, the researchers used a

laboratory technique involving doubly labeled water. They determined

that both groups ate more calories than study foods provided; at six

months the HG group averaged a 16 percent calorie-restricted diet and

the LG group averaged a 17 percent calorie-restricted diet. Although

participants did consume additional calories, the degree of non-

adherence was not significantly different between the LG and HG

groups when measured at various points throughout the study.

" An important difference between our study and other weight-loss

trials is that we did not rely on self-reported intakes, " says Das,

who is also an assistant professor at the Friedman

School. " Underreporting of caloric intake can vary between 5 and 50

percent. By providing the study food for the first six months, we did

not have to worry as much about lifestyle factors like shopping and

cooking habits interfering with dietary change. "

previously conducted a pilot study showing that a diet's

overall glycemic load may be an important determinant of weight loss

for people with high levels of insulin secretion, such as people with

diabetes. " We have observed that for some groups, glycemic load may

impact weight loss. However, in terms of calorie-restricted diets, we

see little difference among diets of varying glycemic load when we

account for factors that affect dietary adherence. "

This work was supported by a grant from the National Institute on

Aging, part of the National Institutes of Health; the USDA; and the

Boston Obesity Nutrition Research Center. For more information about

ongoing recruitment for the second phase of the CALERIE study at

Tufts, call , or visit

http://hnrc.tufts.edu/studies/2520.shtml.

[Guest guest]

In response to Ed White's post, note in the third paragraph:

" We found that the two groups did not differ significantly in their

average body fat loss, energy intake, metabolic rate, or reports of

hunger and satiety. "

While the specifics are not in this article, it seems the researchers

did record measurements regarding the participant's body composition.

Crain

Los Angeles, CA

[Guest guest]

I believe they measured weight loss and called it fat loss.

Ed White

Sandwich, MA USA

derringdoer wrote:

<<<In response to Ed White's post, note in the third paragraph:

" We found that the two groups did not differ significantly in their

average body fat loss, energy intake, metabolic rate, or reports of

hunger and satiety. "

While the specifics are not in this article, it seems the researchers

did record measurements regarding the participant's body composition.>>>