High protein dieters lose more weight, finds McMaster study

Do high protein dieters lose more weight?

A new study from McMaster University has identified a novel relationship between diet, exercise and weight loss.

Researchers put 40 overweight young men through a four week exercise program while cutting their normally required calorie intake by 40 per cent. Half of the participants were given a diet higher in protein then the other the other half, producing a surprising result – the higher-protein dieters lost an average of 10.5 pounds whereas those on the lower-protein diet only lost an average of eight pounds.

Both groups came out stronger and fitter, but the higher-protein group put on an average of 2.5 pounds of extra muscle while the lower-protein group did not add any muscle.

The results show that even under the sub-optimal conditions of calorie deficit, exercise continues to send a signal for muscle mass to be retained.

“We expected the muscle retention but were a little surprised by the amount of additional fat loss in the higher protein consuming group,” says lead researcher Stuart Phillips of McMaster’s Department of Kinesiology.

The connection between diet, exercise and weight loss has been a constant obsession in Canada and the United States for decades. It’s big business, too. Forbes magazine reports that in the U.S. alone, the weight loss market amounts to a 60 billion dollar a year industry.

The issue is also a concern for governments and health care professionals, since the societal effects of obesity are considerable. According to the Canadian Obesity Network, one in four adults in Canada and one in 10 children have clinical obesity, which costs an estimated $6 billion a year to Canadian taxpayers and uses up 6.1 per cent of Canada’s health care budget.

And while the McMaster study may have found an interesting connection between decreased calorie intake and weight loss, the real question remains – can they keep it off? That outcome, unfortunately, seems to be unlikely.

According to the Heart & Stroke Foundation many Canadians are trapped on a “weight loss roller-coaster.” A survey found that 62 per cent of Canadians who lost five or more pounds over the past five years failed to keep the weight off. Furthermore, 70 per cent of overweight or obese people put back all or even more pounds than before.

This comes as no surprise to David Ludwig, professor of nutrition at the Harvard School of Health in Boston, Massachusetts.

In his new book entitled Always Hungry, Dr. Ludwig argues that the problem is not about overeating. Instead, it’s a matter of what you eat and how it affects your body’s response mechanism. Dr. Ludwig states that when we eat highly processed carbohydrates, for example, hormonal changes push our fat cells into a “feeding frenzy” causing them to take in extra calories normally meant for other parts of the body, effectively starving out the other cells and tissues. The brain reads this as a metabolic crisis and responds accordingly, by slowing down the body’s metabolism and, you guessed it, sending out signals that we’re hungry.

That’s why starvation dieting and discipline don’t work, according to Dr. Ludwig. “Cutting back on calories only makes the situation worse. It creates a battle between mind and metabolism that we’re destined to lose.”

Dr. Ludwig suggests a three-step process (involving high fat and eliminating grains, potatoes and added sugars) in order to “calm down” the fat cells and get the body back into a healthy metabolic state.

The McMaster study on high protein dieters was published in the latest issue of the American Journal of Clinical Nutrition.

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