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.
Rule 13.1 acknowledges that a calorie-controlled diet (one in which the intake of energy is lower than its output) is an effective way to lose weight. This rules out unproven ‘fad’ diets and requires marketers to hold evidence in the form of trials on people, where relevant. Marketers are forbidden from combining a calorie-controlled diet with an unproven product and stating or implying that the latter has an effect on weight loss. The ASA has ruled against ads that have included an insignificant reference to a calorie-controlled diet plan while emphasising the role of so-called “slimming pills”, usually with pseudo-scientific sounding explanations (Rule 13.4). Some advertisers “guarantee” consumers will lose weight despite eating “chocolate, cream cakes, crisps etc”. Obviously, the advertiser declined to provide evidence that his herbal product could achieve an average weight loss of 4lbs to 5lbs a week (Babafarid Herbal Remedies, 14 April 2004) and the ASA asked for the ad to be withdrawn. Similar claims were made by another advertiser (The Bristol Group Ltd, 24 September 2008).
Similarly, marketers are forbidden from combining a calorie-controlled diet with a medically-assisted programme of weight-loss which includes prescription-only medications (which cannot be advertised to the public) whether directly stated by name or implied in the advertisement (Strathearn Medical Clinics Ltd, 12 May 2004).
Marketers must hold evidence demonstrating that their diet plans are nutritionally well-balanced (The Bristol Group Ltd, 24 September 2008). The evidence should relate to the type of person who is likely to follow the diet plan (Rule 13.5). If they promote very low calorie diets (those less than 800 calories per day), marketers should advocate them for only short periods and should consider “Obesity: the prevention, identification, assessment and management of overweight and obesity in adults and children” (2006) published by the National Institute for Health and Clinical Excellence (Rule 13.7). Dieters on such restrictive diets should be encouraged to take medical advice beforehand and be regularly monitored.
Marketers of dietary plans or advice should ensure that their claims are backed by sound evidence and are in line with good medical and nutritional practice. CAP and the ASA accept that normally overweight people lose up to 2lbs a week (Rule 13.10). Except in specific circumstances, and with medical advice, weight loss should not exceed 2lbs a week when averaged over several weeks. Weight loss in the first few weeks of a calorie controlled diet may be greater.
Vitamins and minerals do not contribute to weight loss but may be offered to slimmers as a safeguard against nutritional deficiency when dieting (Rule 13.6).
See other entries in the ‘Weight Control’ section.
Last modified : 06 August 2010