Lack of protein causes overeating

Advertisement Human need for protein causes us to overeat: study Our need for protein drives us to overeat, Sydney researchers say. Photo: Istock ShareRead LaterAdjust font size The human need for protein is so powerful we are driven to overeat in our search to consume more of it, Sydney researchers sa Their research has found calorie intake increases as people eat less protein in proportion to other nutrients such as fat and carbohydrates. But don't be fooled into thinking you should start eating protein at the expense of all else, University of Sydney postdoctoral research fellow Alison Gosby said. Advertisement Cathy Wilcox. “We are definitely usually getting the right amount of protein, it's just that we are eating it in the wrong balance with other foods,” she said. When the protein becomes "diluted" by the rest of our diet, we may keep eating more and more calories in search of some kind of hard-wired intake target. This could be prevented by ensuring protein intake is adequate. “The strength of our nutritional drive for protein is frightening within our current nutritional environment, where a large number of low-protein, high-calorie foods are consumed on a regular basis,” she said. People on low incomes are particularly at risk of over-weight and obesity, and may have the most trouble affording protein-rich foods. “When the proportion of protein in a food is low, it is generally cheaper,” she said. “This works on two levels to dilute dietary protein: through the food industry and also through the consumer.” A study in which Dr Gosby was involved found that, when people dropped the proportion of calories they got from protein from 15 per cent to 10 per cent, their overall energy intake shot up by 12 per cent, or about 1000 kilojoules. They also appeared to shift towards snacking on savoury snacks. “We think they were looking for protein,” she said. However, she cautioned that diets above 20 per cent protein produced only small declines in energy intake, and studies on animals indicated they could be unhealthy in the long term. “There are plenty of studies using high-protein diets for weight loss, and they do seem to work very well, but only in the short term, as people don't seem to be able to maintain the increased intake in the long term anyway,” she said. “We are not sure whether there is also a carbohydrate target that needs to be reached, or whether it's just the [current nutritional] environment pushing us away from protein.” The current research, published in the journal Obesity Reviews, included data from 38 trials, concluding that the drive for protein might inhibit the feedback provided by the consumption of carbohydrates and fats. Dietitians Association of Australia spokeswoman Melanie McGrice said it was vital people got the right balance of protein in their diet, which was what made some crash diets particularly concerning. “Diets such as the soup diet or the lemon detox diet are just so bad because they encourage yo-yo dieting and they are bad for your long-term health,” said Ms McGrice, who is an advanced accredited practising dietitian. “Probably one of the biggest problems I see with fad diets is people aren't meeting their protein requirements”. She said part of the reason for conflicting messages about diet was that each person had different needs and foods that worked best for them. “The more overweight someone is the more protein the body requires,” she said. “One of the frustrating things I find is when people try to find a one-size fits all solution when there isn't one.” Dr Gosby's review found the drive for protein seemed to be spread over a one- or two-day period, so not every meal needed to have a high protein content. It is thought a woman of average weight needs at least 46 grams of protein each day, while an average man needs at least 64 grams. Fact Box - Lean meats, tofu, fish, eggs, legumes and beans are all good sources of protein. - Protein and carbohydrate provide about 17 kJ per gram consumed, whereas fat provides about 37 kJ per gram. - The poorest Australians eat the least protein.