Low protein, low GI diet also good for weight loss

In a press release issued on Nov 24, 2010,  University of Copenhagen said its researchers found evidence suggesting that high protein, low glycemic index (GI) diet is the best at preventing weight gain.

The statement may not be 100% accurate, according to the study report in the Nov 25, 2010 issue of The New England Journal of Medicine.

The study led by Thomas Meinert Larsen, Ph.D. and colleagues tested five diets and actually found that only one of the four diets, which had low protein and a high glycemic index, led to significant weight gain during the study period.

The study involved 772 European families with 938 overweight/obese adults with a mean body index of 34 kg/sq meter and 827 children of whom 45 percent were overweight.

Initially, the overweight or obese adults were required to follow an 800 kcal/day diet for eight weeks, which led to an average loss of 11 kg body weight.  Then they were randomly assigned to one of five different low-fat diets for six months.

The five diet types were as follows

A low-protein (13% of calories consumed) diet with a high glycemic index

A low-protein, low-GI diet

A high-protein (25% of calories consumed), low-GI diet

A high-protein, high-GI diet

A diet based on the current dietary recommendations without special instructions regarding GI levels

During the study, a total of 773 adult participants completed the weight loss phase and 548 or 71 percent of them completed the six-month weight maintenance phase.

Fewer people on the high protein and the low-glycemic index diets (26.5% and 25.6 percent respectively) than those on the low-protein-high GI diet (37.4 percent) dropped out the program.

At the end of the study, the researchers found "In the analysis of participants who completed the study, only the low-protein–high-glycemic-index diet was associated with subsequent significant weight regain (1.67 kg; 95% confidence interval [CI], 0.48 to 2.87)."

In an intention-to-treat analysis, the researchers found weight gain was 0.93 kg less in those on a high protein diet than in those on a low-protein diet and 0.95 kg less in those on the low GI diet than those on a high-glycemic index diet.

Dr. T Colin Campbell, a nutrition professor of Cornell University says in his book China Study that a normal person does not have to eat a high protein diet. Around 10 or 11 percent of calories from protein will be sufficient and Americans eat now more than 15 percent protein, which he suggests is excessive.

Dr. Campbell suggests plant-based low protein,low GI diet is the best for maintaining a healthy weight.  He says people can eat as much low protein, low GI diet as they want without having to fear weight gain.

The American Heart Association in 2001 released a statement on dietary protein and weight reduction in Circulation that "Individuals who follow these (high-protein) diets are risk for --- potential cardiac, renal, bone and liver abnormalities overall."

According to the press release by the University of Copenhagen, a diet with high protein contains many protein-rich foods such as lean meat, poultry, fish, eggs, low-fat dairy products, legumes, nuts and almonds.

A low GI diet contains high amounts of whole grain products, unlimited amounts of vegetables and fruits like apples, pears, oranges, raspberries and strawberries, but limited amounts of corn, grapes, kiwi, pineapple, melon and banana. Carrots, beets and parsnip should be eaten raw preferably, according to the release.  

A low GI diet should also avoid sugar, white rice and sugary breakfast products, mashed potatoes and baked potatoes and past should be cooked al dente.

In response to the study, a health observer commented the study seems to suggest that both high protein and low protein diets are good for weight maintenance as long as they have a low glycemic index. 

The researchers were supported by more than 100 food companies for this and other studies, according to the Journal.

Jimmy Downs