The nation’s waistline might be expanding but the UK diet and weight control food market is struggling to increase levels of usage. Total sales of selected categories in the market have risen by a moderate 10% to £1,612 million between 2006 and 2011, with growth being flat in 2011.

Although the number of people who are continually trying to lose weight has increased slightly between 2007 and 2011, the number of adults who have used diet food and drink products has declined over this period.

This report looks at consumers’ attitudes and behaviours related to dieting primarily for weight management, mainly with the use of weight control foods. Mintel's definition of weight control foods includes products designed specifically to help the consumer lose weight and food products that have a reduced fat, calorie or sugar content compared with standard products.

Reduced calorie foods looks at a series of standard food products where calorie levels have been reduced, compared to the standard variant of the product, typically including products labelled as ‘light’ or ‘diet’.

Meal replacements are defined as any meal replacement designed for weight control. This includes meal complements, designed to accompany slimming programmes acting as snack replacements or to accompany a meal.

Meal replacements for weight control are not intended as the sole source of nutrition. They are subject to compositional standards defined in European legislation and must contain the legislated balance of protein, fat, essential fatty acids, vitamins and minerals designed to meet the total nutritional needs of one meal. Mintel, however, does not restrict the market size to those that fall within this category, as there is a blurring in the market and it is not easily identifiable to the consumer which products fall outside this category.

Appetite controllers/suppressants are designed to suppress the natural appetite so that the dieter eats less than usual. They are available as tablets, capsules, lozenges and drinks. Some contain glucose and are claimed to work by raising the blood sugar level, temporarily reducing the appetite. Others contain bulk-forming agents, such as bran, sterculia or methylcellulose and are taken with a drink half an hour before food to give the stomach a feeling of fullness. They are not a substitute for food; they are intended to be used as part of a calorie-controlled diet.

Very-low-calorie diets (VLCDs) are commercially prepared formulae of 800 calories or less that replace all usual food intake. They contain all the nutrients, minerals and vitamins needed to replace normal meals for up to four weeks at a time. They are usually in the form of powdered drinks, soups, pre-mixed drinks and meal bars. VLCDs are generally considered safe when used by dieters with a body mass index (BMI) greater than 25.

Excluded

• special products for specific medical diets – such as gluten-free or those for diabetics

• vitamins, minerals and other supplements such as kelp, which are packaged as helping to fight obesity

• teas and teabags claiming to promote weight loss

• health drinks, such as Complan, which may be used as meal replacements by slimmers, but which are primarily designed as nutritional supplements for the elderly, infirm or those engaged in active sports

• functional foods.