Angeline
Thu, Feb-03-05, 06:07
http://www.theomnivore.com/low_carb_vs_CR_in_obese_kids.html
Anthony Colpo,
February 3, 2005.
Researchers from Marshall University's Joan C. Edwards School of Medicine recently compared the short-term efficacy and safety of two dietary protocols in obese children (mean age, 12 years):
1) a carbohydrate restricted diet ( less than 30 grams per day) with unlimited calories, protein and fat, or;
2) a higher carbohydrate, calorie-restricted diet.
What they did...
The study was explained to the children and their parents, who were then asked to choose between the two dietary protocols. The researchers state that the decision of which diet to follow was made jointly between the children and their parents, with no bias shown by the interviewing dietitian. They were instructed to choose the diet they thought would be easiest to follow and most successful taking into account their own dietary preferences and lifestyle. The amount of follow-up provided was minimal and did not differ between the two groups.
Thirty-six children chose the low-carbohydrate diet, while 16 chose the calorie-restricted diet. A dietitian estimated the energy needs of the children who chose the calorie-restricted diet, then reduced this estimate by twenty percent to stimulate weight loss. They were instructed to consume less than 30% calories from fat, 15% from protein, and 50-55% from carbohydrates. They were encouraged to consume "healthy carbohydrates", including fruits and vegetables, and were discouraged from consuming sugary foods. There was no restriction on carbohydrate-containing drinks, such as milk, fruit juices, or soda.
The high-protein, low-carbohydrate group were instructed on how to count carbohydrates and were told to consume 30 grams or less of carbohydrates per day. No restrictions were placed on protein, fat or total calorie intake, and they were told to eat when hungry. They were allowed to eat any type of carbohydrate; no distinction was made between "good" or "bad" carbs. They were, however, instructed to avoid any beverage containing carbohydrates.
What they found...
Of the original 52 children, seven (19.4%) of the low-carbohydrate dieters failed to return for the 2-month follow-up, as did six (60%) of the calorie-restricted dieters. At the end of the study, the low-carb participants had lost an average of 5.21 kg, while the calorie-restricted group gained an average of 2.36 kg.
It should be noted that this study was not without its flaws. The study was non-randomized, meaning that the participants got to choose their own diets. It is possible that those who selected the high-protein, low-carbohydrate diet were more motivated, became more physically active during the study, or possessed some other characteristic that favored weight loss (the researchers state that they did not emphasize an increase in energy expenditure to participants of either group).
The researchers did not assess dietary compliance, so what this trial was really assessing was the impact of dietary advice rather than dietary protocols as such. Also, it's not difficult to envisage how the advice not to restrict calorie-rich carbohydrate-containing beverages in the energy-restricted group could have disadvantaged their efforts at calorie-restriction.
Therefore, this study cannot be taken as a tightly-controlled comparison of low-carbohydrate and low-fat diets. What it does tell us, however, is that advice to follow a relatively simple and uncomplicated low-carbohydrate protocol produced significant weight loss in obese children in a relatively short time frame. It was also accompanied by a much lower dropout rate than that seen in subjects given calorie-restricted low-fat diet advice.
Reference:
1) Bailes JR, et al. Effect of low-carbohydrate, unlimited calorie diet on the treatment of childhood obesity: A prospective controlled study. Metabolic Syndrome and Related Disorders, Sep 2003; 1 (3): 221-225.
http://www.liebertonline.com/doi/pdfplus/10.1089/154041903322716697
Anthony Colpo,
February 3, 2005.
Researchers from Marshall University's Joan C. Edwards School of Medicine recently compared the short-term efficacy and safety of two dietary protocols in obese children (mean age, 12 years):
1) a carbohydrate restricted diet ( less than 30 grams per day) with unlimited calories, protein and fat, or;
2) a higher carbohydrate, calorie-restricted diet.
What they did...
The study was explained to the children and their parents, who were then asked to choose between the two dietary protocols. The researchers state that the decision of which diet to follow was made jointly between the children and their parents, with no bias shown by the interviewing dietitian. They were instructed to choose the diet they thought would be easiest to follow and most successful taking into account their own dietary preferences and lifestyle. The amount of follow-up provided was minimal and did not differ between the two groups.
Thirty-six children chose the low-carbohydrate diet, while 16 chose the calorie-restricted diet. A dietitian estimated the energy needs of the children who chose the calorie-restricted diet, then reduced this estimate by twenty percent to stimulate weight loss. They were instructed to consume less than 30% calories from fat, 15% from protein, and 50-55% from carbohydrates. They were encouraged to consume "healthy carbohydrates", including fruits and vegetables, and were discouraged from consuming sugary foods. There was no restriction on carbohydrate-containing drinks, such as milk, fruit juices, or soda.
The high-protein, low-carbohydrate group were instructed on how to count carbohydrates and were told to consume 30 grams or less of carbohydrates per day. No restrictions were placed on protein, fat or total calorie intake, and they were told to eat when hungry. They were allowed to eat any type of carbohydrate; no distinction was made between "good" or "bad" carbs. They were, however, instructed to avoid any beverage containing carbohydrates.
What they found...
Of the original 52 children, seven (19.4%) of the low-carbohydrate dieters failed to return for the 2-month follow-up, as did six (60%) of the calorie-restricted dieters. At the end of the study, the low-carb participants had lost an average of 5.21 kg, while the calorie-restricted group gained an average of 2.36 kg.
It should be noted that this study was not without its flaws. The study was non-randomized, meaning that the participants got to choose their own diets. It is possible that those who selected the high-protein, low-carbohydrate diet were more motivated, became more physically active during the study, or possessed some other characteristic that favored weight loss (the researchers state that they did not emphasize an increase in energy expenditure to participants of either group).
The researchers did not assess dietary compliance, so what this trial was really assessing was the impact of dietary advice rather than dietary protocols as such. Also, it's not difficult to envisage how the advice not to restrict calorie-rich carbohydrate-containing beverages in the energy-restricted group could have disadvantaged their efforts at calorie-restriction.
Therefore, this study cannot be taken as a tightly-controlled comparison of low-carbohydrate and low-fat diets. What it does tell us, however, is that advice to follow a relatively simple and uncomplicated low-carbohydrate protocol produced significant weight loss in obese children in a relatively short time frame. It was also accompanied by a much lower dropout rate than that seen in subjects given calorie-restricted low-fat diet advice.
Reference:
1) Bailes JR, et al. Effect of low-carbohydrate, unlimited calorie diet on the treatment of childhood obesity: A prospective controlled study. Metabolic Syndrome and Related Disorders, Sep 2003; 1 (3): 221-225.
http://www.liebertonline.com/doi/pdfplus/10.1089/154041903322716697