Note: This advice is given by the CAP Executive about non-broadcast advertising. It does not constitute legal advice. It does not bind CAP, CAP advisory panels or the Advertising Standards Authority.


Weight gain is often caused by an imbalance of energy intake and energy expenditure. It is generally accepted that physical activity is important for achieving such balance and an increase in exercise is likely to increase energy expenditure. Provided energy intake is maintained at the same level, increasing exercise should result in some weight loss.

• Hold evidence
• Take muscle mass into consideration
• Don’t exaggerate
• Don’t cause offence

Hold evidence

If sufficient evidence is held, it is likely to be acceptable to claim that exercise can help achieve weight loss, inch loss or aid in maintaining a healthy weight when undertaken in conjunction with a calorie-controlled diet.

Claims such as “trim”, “tone”, “tighten” “shape” or “look slimmer” are likely to be acceptable in ads for exercise programmes, but marketers should hold robust evidence to show that the programme is effective at achieving the stated results.

Take muscle mass into consideration

Exercise helps prevent the loss of muscle during calorific restriction. Optimum weight-loss programmes should, therefore, deplete body fat while maintaining lean tissue, by combining a reduction in calorific intake and exercise.

Advertisers should remember that muscle tissue is more dense than fat and as such, exercise designed to increase muscle mass (for example, high-intensity weight training) may not lead to a loss of weight. Marketers of exercise regimes as weight-loss aids should therefore consider this factor when determining the balance between energy input and output.

Don’t exaggerate.

Marketers should ensure they don’t exaggerate the role played by exercise. We understand that exercise is unlikely to be effective at achieving significant weight loss in the absence of dietary change.  
Advertisers should not suggest or imply that exercise regimes will definitely lead to weight or inch loss, that any such loss will be permanent, or that willpower is not required.

Claims that consumers can lose an amount of weight within a stated time period (for example, “lose 8lb in a month”) are not permitted for any weight control products or services. Additionally, claims that customers can lose fat or weight from a particular part of the body are not permitted (Rule 13.9). For types of exercise that focus on particular parts of the body (such as arms of stomach), it may be acceptable to make claims to tone muscles in that area resulting in inch loss, provided they are supported by evidence.    

Don’t cause offence and be responsible.

Weight and body image can be a sensitive subject for many, so take care to ensure you don’t include any claims or images that are likely to cause serious or widespread offence.

Marketers should avoid encouraging weight loss for those who are already a healthy weight.  Claims that exercise can contribute to maintaining a healthy weight alongside a good diet are likely to be acceptable.

See Weight control: GeneralWeight control: Exercise devices and other “Weight control” entries.

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