Several new diets recommend a higher-than-average protein intake. Atkins is probably the best-known and is probably the most extreme. Maybe that is why Atkins is beginning to loose ground to, amongst others, the Zone Diet and the South Beach Diet, both of which allow carbohydrates, and none of them recommend going to bed hungry.
The Zone Diet
… is developed by the physician Barry Sears. In short it entails eating until full, a diet where the ratio between protein, carbohydrates and fat is 7-9-3. After a week on such a diet, one's metabolism is supposed to have been optimized and one will experience a sense of physical and mental well-being, called "the zone", where the body will loose half a kilo every week. When the desired weight is achieved, it is stabilized by increasing the amount of fat in the diet.
The South Beach Diet
… is developed by the cardiologist Arthur Agatson and is originally thought up to tackle cholesterol and blood sugar problems. Like Atkins, it is the first part which is the hardest. During the first two weeks, you cut down on fast carbohydrates such as white bread, potatoes, pasta and fruit. This is meant to alleviate the need for sugar. The following part of the diet is not quite as restrictive. It continues until the desired weight has been achieved, and the last phase is a maintenance phase. The goal of the South Beach Diet is a loss of weight, achieved by healthier eating habits, with more slow carbohydrates and healthier fats.
There seems to be evidence in favour of eating more carbohydrates than allowed by Atkins, and still loosing weight. The argument is that a protein-rich diet is so filling, more than carbohydrates and far more than fat that the total calorie-intake becomes low enough to loose weight.
Proteins Are Filling, and Help You Loose Weight
An American study confirms that a higher ratio of protein gives more satiety, also without eating fewer carbohydrates. The study showed, amongst other things, that during a period of two months, with test-subjects being allowed to eat an unlimited amount of food with a nutritional value of 30 % protein, 20 % fat and 50 % carbohydrate, they still ended up eating 400 calories less a day and loosing 5 kg. of which 4 kg. was body fat.
Of course it is not yet known why protein is so filling, which it obviously is. Research in how appetite-regulating substances work in the body is vigorously being conducted. They may be part of the answer.
Leptine and Ghreline
In the course of the past 10 years, two appetite-regulating hormones which the body makes itself have been discovered: Leptine in 1995 and ghreline in 1999. Leptine is a hormone made in fatty tissue. It signals the brain that there is sufficient energy and thereby the appetite for food is inhibited.
Ghreline works in an opposite fashion. It is made especially by the empty stomach. It makes us feel hungry by affecting the brain's centre for appetite. Diets which involves hunger promotes the production of ghreline, thus tempting us to eat.
It is an important tool to know of the filling effect of protein but it is just as important to know of the difference between fast and slow carbohydrates so that one can avoid the fast (such as sugar, sweets and white bread) as best possible and stick with the slow (for example vegetables and foods rich in fibre), when wanting to loose or just stay at the same weight.
- Barry Sears. Zone Diet Harpercollins 1999. ISBN 0722536925.
- Arthur Agatston. The South Beach Diet. Random House 2003. ISBN 1-57954-646-3
- Astrup A. The satiating power of protein—a key to obesity prevention? Editorial. Am J Clin Nutr 2005; 82: 1-2.
- Weigle DS, Breen PA, Matthys CC, et al. A high-protein diet induces sustained reductions in appetite, ad libitum caloric intake, and body weight despite compensatory changes in diurnal plasma leptin and ghrelin concentrations. Am J Clin Nutr 2005; 82: 41-48.