Why the stars’ eating plans are hard to stomach

DIET: RAW VEGAN

WHAT IT IS: There are many versions but the premise is the same – go vegan and eat raw. Promoted as a cure for obesity and other diseases.

CELEBRITY FANS: Gwyneth Paltrow, Megan Fox, Sting. Miss Paltrow’s website Goop provides recipes for raw vegan food, adding that it ‘ can give your digestive system a break’. BDA VERDICT: A carefully planned vegan diet with the necessary supplements like vitamin B12 and vitamin D can be healthy, but it is not a guarantee of losing weight. A vegan cake is still a cake, vegan syrups are adding sugar and vegan foods often contain the same calories as non-vegan foods.

DIET: ALKALINE

WHAT IT IS: Eating more alkaline food – vegetables such as spinach and broccoli, fruit such as avocado and grapefruit, grains and beans – and avoiding sugar, meat and processed food. This, supporters say, will alter the blood’s PH balance and cut health risks. Some wrongly claim it can treat cancer.

CELEBRITY FANS: Tom Brady, Kate Hudson, Duchess of York. Miss Hudson said: ‘I live by a rulebook of eating alkaline. No meat, no dairy, no gluten. I try to stay away from sugar.’

BDA VERDICT: You’ll most likely lose weight as you are cutting out processed foods and eating more healthily – [but it’s] nothing to do with acid or alkali nonsense.

DIET: KATIE PRICE’S SUPPLEMENTS

WHAT IT IS: Includes hydration, breakfast and meal replacements. The supplement powder is added to water or milk to make a drink.

CELEBRITY FANS: Katie Price. She said: ‘Used as part of a healthy diet to replace a meal or snack and combined with an active lifestyle, Meal Replacement provides a balanced and nutritious solution to help towards your weight loss goals.’

BDA VERDICT: Protein supplements are often missold as the only answer to weight loss, often with misleading claims attached … Rapid weight loss can be a powerful motivation, but it is unsustainable.

DIET: PIOPPI

WHAT IT IS: Named after an Italian village recognised as the home of the traditional Mediterranean diet, it’s lowcarb and high-fat. It means eating lots of vegetables, nuts, legumes and fish and refraining from red meat, starchy carbs and sweetened treats. Followers are encouraged to fast for 24 hours at a time every week.

CELEBRITY FANS: Keith Vaz, Andy Burnham. Mr Vaz, of the All- Party Parliamentary Diabetes Group, urged 100 MPs with the highest prevalence of type 2 diabetes in their constituencies to follow the plan over summer.

BDA VERDICT: Probably not a good idea. A Mediterranean diet is a healthy choice but this has been hijacked here. Fasting may help weight loss but the only reason their other advice is likely to help is because it involves less food and calories.

DIET: KETOGENIC

WHAT IT IS: Many types including Atkins and Paleo but all very low-carb, relatively high in fat and moderate protein. Excludes grains, dairy, legumes, soy, most fruit and starchy vegetables. Carbohydrate comes mainly from non-starchy vegetables, nuts and seeds.

CELEBRITY FANS: Kim Kardashian, Halle Berry, Mick Jagger, Tom Jones, Rihanna. Miss Berry said: ‘Train your body to burn healthy fats – avocado, oil, coconut oil, butter, but no sugar … you’re constantly on fat-burning mode, that’s the secret.’

BDA VERDICT: The diet cuts total calories and removes foods people tend to overeat. Initial side effects may include low energy levels, brain fog, increased hunger, sleep problems, nausea, digestive discomfort and poor exercise performance. It can be an effective method of weight loss in the short term with careful planning but it is hard to sustain in the long term.