SOME WELL KNOWN DIET PLANS

Diets in most books and magazines advocate energy restriction. Some, such as ‘The Complete F-Plan Diet’ and The Pritikin Program’, are based on credible information, incorporating a high-carbohydrate/fibre, low-fat eating plan, although they tend to be extreme and may be difficult to sustain for a lifetime. Less reasonable but readily available diets that either exclude foods or are based on unsupported claims include:

‘Rotation Diet’. This diet varies energy intake from 600 to 1500kcal/day over a period of 4 weeks. It then provides for a maintenance dietary intake of 1800kcal/day, which increases the likelihood of micro-nutrient inadequacy. The basic premise of this diet is that by rotating energy intakes for weight loss, a rise in resting metabolic rate is achieved. This is NOT supported by research.

‘Fit for life’. Probably one of the most widely talked about diets available, this diet is low in milk, meat, breads and cereals, and very high in fruit and vegetables. Encouraging people to eat more fruit and vegetables is desirable, however the diet is based on unsupported claims that rat is accumulated by improper food combinations. It also misinterprets digestive physiology, particularly gastric emptying, and claims that certain macronutrient combinations ‘rot’ in the stomach and release ‘toxins’. These claims are NOT supported by research. Refer to Rosemary Stanton’s The Diet Dilemma for a more extensive review of this diet.

The Dr Atkins Diet’ and The Drinking Man’s Diet’. These diets are based on carbohydrate restriction. Adequate carbohydrate is required to maintain blood glucose levels, fluid balance and to spare amino acids from being used as a fuel source. Approximately 100 grams of carbohydrate per day is required to achieve the above and to avoid ketosis. Many examples of low-carbohydrate diets have existed over the years and these diets cause diuresis and loss of fluid weight in the first few days due to glycogen and fluid loss. Protein is catabolised contributing to a further fluid and weight loss. Other side effects apart from dehydration include fatigue, postural hypotension, taste changes, halitosis and altered biochemical parameters. Adequate fluid and carbohydrate intake are two nutritional recommendations that are NOT met by this form of diet.

*135\186\4*