Fad diets

There are always lots of 'wonder' diets being promoted in the media which portray weight loss as something magical rather than something based on scientific facts and research. Many of these diets may promote restriction of one or more food groups, specific food combinations or recommend bizarre quantities of one type of food.

This leads to an unbalanced diet short in nutrients, and one of the reasons people tend to lose weight on them is that they restrict food intake so much that their calorie intake is reduced. Also, because they are so restrictive people tend to only follow them for a short period of time, and many also have unpleasant side effects that also reduce the length of time they are followed.

It is likely to be a fad diet if they:

• Recommend magical fat-burning foods e.g. grapefruit
• Recommend avoiding a whole food group
• Suggest eating only one type of food e.g. cabbage soup
• Suggest rigid menus that limit food choice.
• Recommend eating foods in particular combinations
• Suggest rapid weight loss (more than 2lbs a week)
• Promise a quick fix
• Make claims that sound too good to be true.

The Atkins Diet

This is one of the main diets that has been in the media a lot over the last few years and involves restricting intake of carbohydrate (initially to a level of 20g a day) whilst indulging in foods high in protein and fat.

Despite its popularity there is very little scientific research on this diet, and all of the studies done so far are short term. Although initial weight loss is often slightly higher when a low carbohydrate and a low fat diet have been compared, in the longer term i.e. a year, there is no difference between the diets.

Because there are no long term studies on the Atkins diet at the moment there are also many concerns about its affect on long term health including the heart, kidneys, liver and bone. Concerns raised about low carbohydrate diets include:

• A low carbohydrate diet can lead to ketosis, which could be serious for people with diabetes. The side effects of ketosis are weakness, nausea, dehydration and bad breath
• Much of the initial weight loss is due to loss of glycogen stores (the body's carbohydrate stores) and fluid.
• Cutting out carbohydrate could lead to low intakes of vitamins and minerals.
• A low fibre intake could lead to constipation.
• The excess protein intake may cause calcium losses from the body that could adversely affect bone health over the longer term.
• Although there are no long term studies into the Atkins diet, there is a concern that the high amounts of fat and saturated fats, and low amounts of fruit and vegetables and fibre could lead to a greater risk of cardiovascular disease.
• In theory a high protein diet could put strain on the kidneys and more research is needed on the effects of the diet on long term kidney function.

The British Dietetic Association does not recommend the Atkins diet as the best approach for healthy weight control.

The above information was taken from the British Dietetic Association's website.