Q
Quentin Grady
Guest
G'day G'day Folks,
I have looked at this experiment and am left wondering what really was going on and what
really happened.
The control diet (41% fat, 14% protein, 45% carbohydrates and 7 g of fiber per 1000 kcal)appears to
be a reasonable approximation of the standard American diet, SAD.
The intervention diet (18% fat, 19% protein, 63% carbohydrates, and 26 g of fiber per 1000 kcal)
IF we take the research results at face value then raising the protein from a maintenance level of
14% to 19% and dramatically raising the fibre from 7 g per 1000 kcal to 28 g per 1000 kcal worked.
Both protein and fibre are known to promote satiety so that stacks the odds in an ad libertum trial.
Weight loss is easier with higher protein levels.
If the researchers had wanted a fair trial of some other factor, say carbohydrate for instance, then
the control diet would have had 18 or 19 g of fibre per 1000 kcal. Obviously there was a massive yet
largely undisclosed difference in the quality of carbohydrates used in the control and intervention
arms of the trial. At the moment the trial appears to be a poorly conducted trial of carbohydrate
composition. It would have been more meaningful if the possible confounding factor of carbohydrate
percentages etc had been eliminated.
OK, the reasons for their success aren't too hard to find if we assume that in this ad libertum
trial, people on the intervention trial consumed fewer calories over time when given almost four
times the fibre and a higher than maintenance level of protein.
However there is a rub.
The authors claim "There was no significant difference in total food intake among the 3 groups and
no change in energy intake over time."
Were they brazenly hoping no one would check out what exactly "no significant difference" meant or
was there some incompetence in their method of assessing energy intake that was almost immediately
picked up by others or are their detractors simply wrong and making up refutations as they go along.
http://www.foxnews.com/story/0,2933,109890,00.html
"As it turns out, study subjects in the high-carbohydrate groups consumed about 400-600 calories
less per day than those in the control group. Over the 12-week period of the study, then, the
average study subject in the high-carbohydrate group consumed about 42,000 calories less than the
average study subject in the control group.
Since a pound of fat represents about 3,500 calories, it’s no wonder why those in the high-
carbohydrate group lost weight. It was because they ate less, not because of any magical effects of
a high-carbohydrate diet."
How on Earth could that happen? .
Did the researchers count the fibre as carbohydrate in their energy calculations?
Were they hoping no one would notice the difference in energy intake or ask if they were indeed
significant?
Are we to believe that not one of them thought to check the energy figures? If any of them had
doubts are we to believe none of them asked for an independent audit?
Books have been written about group decision making. The perils aren't new or unknown. Hays NP,
Starling RD, Liu X, Sullivan DH, Trappe TA, Fluckey JD, Evans WJ. all put THEIR names to the
research. Did none of the seven think their reputations worthy of having an independent audit before
publication?
For that matter, how on Earth could the paper be published without having undergone preliminary
scrutiny? By now scientific publishers and scientists alike must have some realisation that ficts on
controversial topics propagate rapidly without much hope of retrieval. IMHO when published research
is shown to be wanting in basic accountancy audit issues the reputation of all scientists and
scientific publishers is ever so slightly tarnished in the public mind.
And what of the Donald W. Reynolds Department of Geriatrics, University of Arkansas?
How functional are THEIR review committees?
Do universities whose reputations depend in part on research quality have validation committees and
how are they accredited? We are not talking about esoteric matters of scientific opinion here ...
just basic energy accounting on which the public should be able to rely.
Firstly I'd like to know what really happened in this experiment.
There are millions of people who could benefit from some sound scientific research on weightloss.
They deserve something better than the scientific community is apparently currently delivering if
this is a typical example.
Once it is established beyond reasonable doubt what really happened, the next question would seem to
be how to set and maintain standards for research that will uphold the reputation of science.
If funding realities have made research commercial perhaps it is high time a bond system was
instituted to ensure adequate checks are made of the validity of interpretation of data before
publication. Someone can work out the details. There are existing models such as fidelity funds for
lawyers that might provide a basis for discussion.
1: Arch Intern Med. 2004 Jan 26;164(2):210-7.
Effects of an ad libitum low-fat, high-carbohydrate diet on body weight, body composition, and fat
distribution in older men and women: a randomized controlled trial.
Hays NP, Starling RD, Liu X, Sullivan DH, Trappe TA, Fluckey JD, Evans WJ.
Nutrition, Metabolism, and Exercise Laboratory, Donald W. Reynolds Department of Geriatrics,
University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System,
Little Rock.
BACKGROUND: The efficacy of ad libitum low-fat diets in reducing body weight and fat in overweight
and obese adults remains controversial.
METHODS: We examined the effect of a 12-week low-fat, high-complex carbohydrate diet alone (HI-CHO)
and in combination with aerobic exercise training (HI-CHO + EX) on body weight and composition in 34
individuals with impaired glucose tolerance (20 women and 14 men; mean +/- SEM age, 66 +/- 1 years).
Participants were randomly assigned to a control diet (41% fat, 14% protein, 45% carbohydrates, and
7 g of fiber per 1000 kcal), a HI-CHO diet (18% fat, 19% protein, 63% carbohydrates, and 26 g of
fiber per 1000 kcal), or a HI-CHO diet plus endurance exercise 4 d/wk, 45 min/d, at 80% peak oxygen
consumption (HI-CHO + EX). Participants were provided 150% of estimated energy needs and were
instructed to consume food ad libitum. Total food intake, body composition, resting metabolic rate,
and substrate oxidation were measured.
RESULTS: There was no significant difference in total food intake among the 3 groups and no change
in energy intake over time. The HI-CHO + EX and HI-CHO groups lost more body weight (-4.8 +/- 0.9 kg
[P =.003] and -3.2 +/- 1.2 kg [P =.02]) and a higher percentage of body fat (-3.5% +/- 0.7% [P =.01]
and -2.2% +/- 1.2% [P =.049]) than controls (-0.1 +/- 0.6 kg and 0.2% +/- 0.6%). In addition, thigh
fat area decreased in the HI-CHO (P =.003) and HI-CHO + EX (P<.001) groups compared with controls.
High carbohydrate intake and weight loss did not result in a decreased resting metabolic rate or
reduced fat oxidation.
CONCLUSION: A high-carbohydrate diet consumed ad libitum, with no attempt at energy restriction or
change in energy intake, results in losses of body weight and body fat in older men and women.
PMID: 14744846 [PubMed - in process]
Best wishes,
--
Quentin Grady ^ ^ / New Zealand, >#,#< [ / \ /\ "... and the blind dog was leading."
http://homepages.paradise.net.nz/quentin
I have looked at this experiment and am left wondering what really was going on and what
really happened.
The control diet (41% fat, 14% protein, 45% carbohydrates and 7 g of fiber per 1000 kcal)appears to
be a reasonable approximation of the standard American diet, SAD.
The intervention diet (18% fat, 19% protein, 63% carbohydrates, and 26 g of fiber per 1000 kcal)
IF we take the research results at face value then raising the protein from a maintenance level of
14% to 19% and dramatically raising the fibre from 7 g per 1000 kcal to 28 g per 1000 kcal worked.
Both protein and fibre are known to promote satiety so that stacks the odds in an ad libertum trial.
Weight loss is easier with higher protein levels.
If the researchers had wanted a fair trial of some other factor, say carbohydrate for instance, then
the control diet would have had 18 or 19 g of fibre per 1000 kcal. Obviously there was a massive yet
largely undisclosed difference in the quality of carbohydrates used in the control and intervention
arms of the trial. At the moment the trial appears to be a poorly conducted trial of carbohydrate
composition. It would have been more meaningful if the possible confounding factor of carbohydrate
percentages etc had been eliminated.
OK, the reasons for their success aren't too hard to find if we assume that in this ad libertum
trial, people on the intervention trial consumed fewer calories over time when given almost four
times the fibre and a higher than maintenance level of protein.
However there is a rub.
The authors claim "There was no significant difference in total food intake among the 3 groups and
no change in energy intake over time."
Were they brazenly hoping no one would check out what exactly "no significant difference" meant or
was there some incompetence in their method of assessing energy intake that was almost immediately
picked up by others or are their detractors simply wrong and making up refutations as they go along.
http://www.foxnews.com/story/0,2933,109890,00.html
"As it turns out, study subjects in the high-carbohydrate groups consumed about 400-600 calories
less per day than those in the control group. Over the 12-week period of the study, then, the
average study subject in the high-carbohydrate group consumed about 42,000 calories less than the
average study subject in the control group.
Since a pound of fat represents about 3,500 calories, it’s no wonder why those in the high-
carbohydrate group lost weight. It was because they ate less, not because of any magical effects of
a high-carbohydrate diet."
How on Earth could that happen? .
Did the researchers count the fibre as carbohydrate in their energy calculations?
Were they hoping no one would notice the difference in energy intake or ask if they were indeed
significant?
Are we to believe that not one of them thought to check the energy figures? If any of them had
doubts are we to believe none of them asked for an independent audit?
Books have been written about group decision making. The perils aren't new or unknown. Hays NP,
Starling RD, Liu X, Sullivan DH, Trappe TA, Fluckey JD, Evans WJ. all put THEIR names to the
research. Did none of the seven think their reputations worthy of having an independent audit before
publication?
For that matter, how on Earth could the paper be published without having undergone preliminary
scrutiny? By now scientific publishers and scientists alike must have some realisation that ficts on
controversial topics propagate rapidly without much hope of retrieval. IMHO when published research
is shown to be wanting in basic accountancy audit issues the reputation of all scientists and
scientific publishers is ever so slightly tarnished in the public mind.
And what of the Donald W. Reynolds Department of Geriatrics, University of Arkansas?
How functional are THEIR review committees?
Do universities whose reputations depend in part on research quality have validation committees and
how are they accredited? We are not talking about esoteric matters of scientific opinion here ...
just basic energy accounting on which the public should be able to rely.
Firstly I'd like to know what really happened in this experiment.
There are millions of people who could benefit from some sound scientific research on weightloss.
They deserve something better than the scientific community is apparently currently delivering if
this is a typical example.
Once it is established beyond reasonable doubt what really happened, the next question would seem to
be how to set and maintain standards for research that will uphold the reputation of science.
If funding realities have made research commercial perhaps it is high time a bond system was
instituted to ensure adequate checks are made of the validity of interpretation of data before
publication. Someone can work out the details. There are existing models such as fidelity funds for
lawyers that might provide a basis for discussion.
1: Arch Intern Med. 2004 Jan 26;164(2):210-7.
Effects of an ad libitum low-fat, high-carbohydrate diet on body weight, body composition, and fat
distribution in older men and women: a randomized controlled trial.
Hays NP, Starling RD, Liu X, Sullivan DH, Trappe TA, Fluckey JD, Evans WJ.
Nutrition, Metabolism, and Exercise Laboratory, Donald W. Reynolds Department of Geriatrics,
University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System,
Little Rock.
BACKGROUND: The efficacy of ad libitum low-fat diets in reducing body weight and fat in overweight
and obese adults remains controversial.
METHODS: We examined the effect of a 12-week low-fat, high-complex carbohydrate diet alone (HI-CHO)
and in combination with aerobic exercise training (HI-CHO + EX) on body weight and composition in 34
individuals with impaired glucose tolerance (20 women and 14 men; mean +/- SEM age, 66 +/- 1 years).
Participants were randomly assigned to a control diet (41% fat, 14% protein, 45% carbohydrates, and
7 g of fiber per 1000 kcal), a HI-CHO diet (18% fat, 19% protein, 63% carbohydrates, and 26 g of
fiber per 1000 kcal), or a HI-CHO diet plus endurance exercise 4 d/wk, 45 min/d, at 80% peak oxygen
consumption (HI-CHO + EX). Participants were provided 150% of estimated energy needs and were
instructed to consume food ad libitum. Total food intake, body composition, resting metabolic rate,
and substrate oxidation were measured.
RESULTS: There was no significant difference in total food intake among the 3 groups and no change
in energy intake over time. The HI-CHO + EX and HI-CHO groups lost more body weight (-4.8 +/- 0.9 kg
[P =.003] and -3.2 +/- 1.2 kg [P =.02]) and a higher percentage of body fat (-3.5% +/- 0.7% [P =.01]
and -2.2% +/- 1.2% [P =.049]) than controls (-0.1 +/- 0.6 kg and 0.2% +/- 0.6%). In addition, thigh
fat area decreased in the HI-CHO (P =.003) and HI-CHO + EX (P<.001) groups compared with controls.
High carbohydrate intake and weight loss did not result in a decreased resting metabolic rate or
reduced fat oxidation.
CONCLUSION: A high-carbohydrate diet consumed ad libitum, with no attempt at energy restriction or
change in energy intake, results in losses of body weight and body fat in older men and women.
PMID: 14744846 [PubMed - in process]
Best wishes,
--
Quentin Grady ^ ^ / New Zealand, >#,#< [ / \ /\ "... and the blind dog was leading."
http://homepages.paradise.net.nz/quentin