Australasian Science: Australia's authority on science since 1938

Protein Is the Key to Weight Loss

By Stephen Luntz

A new line of evidence has been produced to support the theory that overeating is largely driven by inadequate protein content in the modern diet.

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“Humans have a particularly strong appetite for protein, and when the proportion of protein in the diet is low this appetite can drive excess energy intake,” says Dr Alison Gosby of the University of Sydney’s School of Biological Sciences.

Gosby conducted a study where a group of 22 volunteers spent 4 days each on diets where 10%, 15% and 25% of the energy came from protein while fat content was held constant.

Remarkably, the foods were prepared so that each menu was rated as equally appetising, and participants in the study did not know which menu they were on during the week.

No statistically significant difference was found between food consumption on the 15% and 25% diets, but those on the 10% protein diet took in 12% more energy with 70% of this increase due to snacking.

The findings support the protein-leverage theory of co-author Prof Steve Simpson of the University of Sydney. “Our previous work on slime moulds, insects, fish, birds, rodents, mink, cats and monkeys has shown that animals have separate appetites for protein, fat and carbohydrate. Interestingly, if protein in the diet is diluted, even by a small amount by extra fat and carbohydrate, the appetite for protein dominates and they will keep eating in an attempt to attain their target level of protein,” Simpson says.

It is notoriously difficult to control diets for...

The full text of this article can be purchased from Informit.