Fab or fad diets? The facts on weight loss.

After scanning the scene, here's what we discovered about the following fads:

The Zone Diet contains carbohydrate (40%), protein (30%) and fat (30%) as a fixed percentage of food intake at each meal. The Zone Diet is an energy-restricted diet and it is recommended that a meal or snack is eaten at least every five hours that fits the above percentage profile. Achieving the exact ratios every meal may be difficult in practice. As with any energy restricted diet, The Zone Diet can aid weight loss but often when the diet is stopped previous food habits resume and weight may increase. There is no evidence at present to suggest that The Zone Diet has any benefit over other versions of calorie controlled eating.

The Atkins Diet is high in protein and fat, and low in carbohydrate foods. It is low in fibre due to the limitation on carbohydrates and may also be lacking in some vitamins, minerals and antioxidants, especially in the initial phases of the diet. The initial stage (minimum of two weeks) of the program recommends no more than 20g of carbohydrate per day. It seems that the maintenance amount of carbohydrate for a regular exerciser is upwards of 90g for daily functioning. Given the restrictions on carbohydrate intake, artificial sweeteners are promoted to replace natural sugars for sugarless sweet treats. Although reasonably effective for short term weight loss, long term effectiveness for weight loss is not well established.

A recent study suggested that a low carbohydrate diet (The Atkins Diet) versus a low fat diet was more favourable in terms of weight loss but has more adverse effects such as headaches, halitosis and constipation. Weight loss in both diet forms resulted predominately from reduced energy intake. However another study found similar weight loss outcomes between a low carbohydrate diet versus a calorie controlled low fat diet.

The Pritikin Diet containing approximately 80% carbohydrate intake has been shown to prevent and possibly reverse atherosclerosis when combined with stress reduction and exercise. It is high in fibre, low in fat and aerobic exercise is promoted as an integral component. It is recommended that fat intake be less than 10% of total energy intake and this may also minimise the intake of essential fatty acids.

A Low GI Diet is based on eating specific types of carbohydrate foods in a moderate to high percentage of the total dietary intake. It advocates lower fat, especially saturated fats, and average amounts of protein. The glycaemic index (GI) is derived from physiological measurements and indicates carbohydrate quality. Carbohydrates that when digested, create a fast blood glucose response are referred to as high GI foods and those that create a slower blood glucose response are the low GI foods. Low GI foods are more favourable as part of a weight loss program. Eating mainly low GI foods can benefit diabetics and may also address obesity and heart disease through improving blood cholesterol and triglycerides. For more information on the GI of various foods see the glycaemic index online:

The wash up

Fad Diets generally lack scientific evidence, have rigid menus and often overlook the need to exercise. They often consist of 'one food' type diets such as the grapefruit or banana which encourage eating one food type while excluding other nutritional choices. These diets tend to be nutritionally unbalanced and can lead to poor eating habits.

Commercial Diets that involve strategies for education and support with prepackaged meals or rules for eating regular foods are generally nutritionally balanced and energy restricted. Although they may help with short term weight loss there is lack of data to support their effectiveness for long term weight management. Commercial diets that allow regular food and not prepackaged meals are preferred as you can make your own healthful food choices within the rules of that diet long after the program has finished.

The best option

A healthful diet needs to:

• Contain adequate water (about 2.5L daily in most cases)
• Avoid foods with a high sugar, fat or salt content
• Minimise foods containing trans-fatty acids
• Minimise foods with chemical additives and preservatives

Exercise: Lifestyle based increases in physical activity are more likely to lead to successful long term weight loss as opposed to a structured exercise program. Improvements in body weight can be obtained by accumulating 30 minutes per day of moderately intense exercise such as a brisk walk. Recommendations about the type, intensity, duration and frequency of exercise will depend on your client, and their health and fitness levels. Suggesting simple lifestyle changes to increase physical output initially may lead to a sustained exercise regime in the future.

One of the most effective methods for achieving goals in weight loss is to write a food diary as well as keep track of exercise sessions and daily feelings about the process. Including more healthful choices when shopping, shopping from a pre-written list or leaving the table as soon as the meal is finished are just some of the many lifestyle modification strategies to be considered.

Traditionally, naturopaths have used nutritional factors and herbs to support liver function as an important component of the weight loss process. A detoxification diet can be followed using sound nutritional principles with herbs and nutrients to aid the process.

If you have any questions regarding a healthy approach to weight management, contact our free Advisory Service on 1800 803 760.

References available on request