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.
Be aware of the general rules on testimonials and endorsements.
Remember that customer testimonials are not evidence of efficacy.
Take care with references to rates or amount of weight loss.
Be mindful of testimonials about obesity.
Be aware of additional rules on foods and food supplements.
Be aware of the general rules on testimonials and endorsements.
There are rules in the CAP Code that relate to the use of testimonials in all marketing communications, including those for weight control products and services (rules 3.34 to 3.48)
The rules indicate that testimonials should only be used in marketing communications if they are relevant, demonstrably genuine and used with permission. See CAP Advice on Testimonials and endorsements.
Additionally, factual claims in testimonials, including those for weight control products and services, must not mislead. See CAP Advice on Factual claims in testimonials and endorsements
Remember that customer testimonials are not evidence of efficacy.
The Weight Control section of the Code specifically refers to testimonials and states that testimonials that are not supported by trials do not constitute substantiation (Rule 13.1). Marketers must therefore hold scientific evidence that proves the general efficacy of their product (Miruji Health & Wellbeing, 12 May 2012, Shop TJC Ltd, 21 June 2023 and Bio-Medical Research Ltd, 10 March 2021). See Rule 13.1 and the CAP guidance on the level of substantiation expected in health, beauty and slimming claims).
The ASA investigated an ad which stated, “I've cut my insulin from 40 units to 12 units and I am hoping to be insulin free by the end of next month” and “I used to suffer from regular tension headaches ... these have disappeared". The ASA was not provided with convincing evidence to substantiate those claims. It also considered the implied claims to treat diabetes would discourage essential medical treatment because the treatment was not carried under the supervision of a suitably qualified health professional (rules 12.1, 12.2) (Zoë Harcombe, 3 December 2014)
Take care with references to rates or amount of weight loss.
Marketers should avoid including testimonials which either state or imply that other users of the service could potentially lose a precise amount of weight within a stated period of time (13.9). It is worth noting that, if documented and substantiated, and in line with good nutritional practice, marketers are likely to be able to include testimonials which claim that specific individuals have previously lost exact amounts of weight in a given period (13.10). (Easylife Group Ltd 23 December 2023)
CAP understands that in line with Department of Health and Social Care (DHSC) advice, the acceptable safe weight-loss limit for those who are overweight is 2lbs a week. Claims of a higher rate of weight loss for those who are overweight will typically be considered problematic. Claims like “Lose over a full stone in just 2-4 weeks” and “I’ve been on it for a week so far and have lost 7 pounds” are unacceptable because these rates of weight loss are not compatible with good medical and nutritional practice. (Skinny Revolution Ltd, 7 October 2020) Easylife Group Ltd 23 December 2020
Conversely, “I lost 8lbs in six weeks on the recommended diet plan!” is an acceptable claim, provided the general efficacy of the programme has been substantiated, the marketer holds signed and dated proof that the testimonial is genuine and has the subject’s permission to use it (3.48).
CAP and the ASA regard the use of before and after photos in the same way as testimonials. Marketers should therefore ensure that they meet the requirements of rules 3.45 to 3.48 of the CAP Code. They should hold signed and dated proof that the photos are genuine and have not been manipulated. Before and after pictures should not exaggerate the impact of the advertised product or treatment (Lipstick Gangster Ltd, 12 July 2023).
Be mindful of testimonials about obesity.
Obesity in adults is defined by a Body Mass Index (BMI) of more than 30 kg/m2. Obesity is frequently associated with a medical condition and rules 12.2 and 13.2 state that marketers should not offer specific advice on, diagnosis of or treatment for it unless it is conducted under the supervision of a medical doctor or other suitably qualified health professional. (Miruji Health & Wellbeing, 2 May 2012). See Weight control: Obesity.
Be aware of additional rules on foods and food supplements
Marketers promoting a food (including soft drinks) or food supplements should take the Food Rules into account and note that weight loss and other claims of this nature, which directly result in an effect on one’s health, are considered to be health claims. A health claim for a food should not be made unless that claim is compatible with an authorised claim listed on the GB (NHC) Register of nutrition and health claims. See Weight control: Food and Food Supplements.
Even if a marketer holds signed and dated proof to show that before and after photos are genuine, the visual claims implied by the photos may render them problematic if they are seen to go beyond the meaning of an authorised claim on the relevant register (Premium Health Europe BV - ASA | CAP 19 April 2023).
Finally, claims of a rate or amount of weight loss are prohibited for foods and food supplements (15.6.6). (Happy Koala LLC 17 July 2024 and Happy Koala LLC, 3 July 2024)
See Weight control: General, Weight control: Food and Food supplements, Weight control: Medical procedures, Weight control: Exercise, Weight control: Pills, medicines and patches, Weight control: Claims in names, Testimonials and endorsements, Before and after photos