Low carbohydrate diets

In low carbohydrate diets, fruit, cereal, bread and vegetables are identified as the ‘bad foods’ as they contain carbohydrates, but there are serious consequences of removing these food products from the diet. In the short term their exclusion can lead to feeling run-down, a lack of energy and constipation. Long-term exclusion could lead to various conditions including kidney damage and high cholesterol. In fact, the long-term side-effects of a low carbohydrate diet are still not fully known.

Low carbohydrate diets can be very confusing and may lead to people cutting out healthy carbohydrate foods, i.e. fruit, vegetables, wholegrain, in favour of high-fat foods. The health benefits of fruit, vegetable and wholegrain include their high vitamin and mineral contents as well as fibre. High consumption of these foods can decrease risks of heart disease, diabetes and cancers.

There are some benefits of a high protein-low carbohydrate diet compared to a low fat-high carbohydrates diet with regards to speed of weight loss. Studies have shown that for the first 6 months, weight loss is more dramatic in the low carbohydrate diet but after a year the weight loss is the same, independent of which diet the person is following.

The safe amount of weight to lose per week is 1 kilogram. If a person is losing more than this amount a week it is likely that they are losing water and lean body mass rather than fat. It is important not to lose lean body mass as it then means the body requires less energy to maintain the same amount of weight, so a person has to eat less and less to lose more weight. Usually weight losses of more than 1 kilogram per week will not be sustainable and a person will end up putting the weight back on.

Fibre-rich foods in weight-reducing diets have fewer calories gram for gram than foods with high fat content and give a feeling of fullness and satiety. In low carbohydrate diets, there can be higher than usual intakes of saturated fats because high-protein foods may also contain high levels of fat. Diets containing high levels of fats can increase the risk of heart disease. Increased protein intake also causes an extra strain on the kidneys and can increase the amount of calcium excreted from the body, thereby affecting bone growth and restructure.

Following a diet with too many restrictions can be difficult to maintain. In the case of low carbohydrate diets the restriction on food choices means that the diet becomes dull and unpalatable, leading to a lack of motivation to continue and then a lapse back to unhealthy eating habits.

Many nutritionists would recommend that the most successful way to lose weight is by following a balanced diet which includes a moderate intake of a variety of foods. This diet needs to become a long-term lifestyle change rather than a diet. Although weight-loss results may be slower than a fad diet the long-term benefits are positive. It is better to balance calorie intake and exercise than to exclude carbohydrates altogether.