Is a liquid lunch the best way to keep excess weight at bay?

Whether it’s for your summer holiday, to fit into a special dress or just to feel better, most of us have tried a diet at some point in our life.  But while many opt for calorie counting or the 5:2, when it comes to shifting the pounds quickly, liquid meal replacements are becoming increasingly popular. Instead of tucking into a calorie-controlled plate of meat and two veg, your breakfast, lunch and dinner is a formula milkshake or soup for weeks. But do these extreme diets actually work and, more crucially, are they any good for long-term weight loss or do you just pile the pounds back on once you start eating “proper” food again? A growing number of experts believe that these total meal replacement diets (also known as total diet replacements or formula diets) could be the solution to solving the UK’s obesity crisis – they are, in fact, already being used by the NHS in some areas of the country. These diets by law provide all your necessary nutrients in just 450–800 calories a day – something not possible with the food equivalent.  However, until recently, experts wrote them off as quick fixes that didn’t work for long because they didn’t retrain eating habits. “A newer approach is to combine a period of total diet replacement with nutritional education, behaviour-change strategies and support,” explains Prof Mike Lean of University of Glasgow’s Human Nutrition department. “On them, people can lose two to three stone in eight to 12 weeks, compared with under one stone, on average, on a conventional diet. “This is very motivating and the food-free period offers a break from the habits that led to obesity. Food is then reintroduced gradually and behaviour change tackled.” Fresh approach This is the format followed by Counterweight Plus, a weight loss and maintenance programme developed and tested by healthcare professionals, mainly under Scottish government funding. Available so far on the NHS in five Scottish and one English region, with a number of other areas to follow, it includes a total diet replacement lasting 12 weeks followed by a programme to reintroduce healthy foods. During that time, people learn strategies to swap bad habits for good and get support for up to two years. A 2013 study reported in the British Journal of General Practice found that at least a third of those who started the programme had kept off a weight loss of 2st 5lb after a year with some losing 4st 10lb or more. It proved far more cost-effective than bariatric surgery. Better still, earlier this year, the longest ever follow-up study at the University of Copenhagen on people who had lost weight on total diet replacements found that after four years, 56% had maintained their original 10% weight loss. Diabetes reversal But most exciting is the potential for the diets to combat diabetes. In 2011, a small study at Newcastle University showed that after eight weeks on a 600-calorie-a-day liquid formula diet, volunteers with type 2 diabetes found it had disappeared. “If successful, this could revolutionise diabetes treatment,” says Professor Anthony Leeds, an obesity specialist at the Central Middlesex Hospital and medical director of the Cambridge Weight Plan. Can anyone use them? But if you don’t have type 2 diabetes and are overweight rather than obese, could these diets still work for you? “People who are overweight can use formula diets but they don’t need to consume fewer than 800 calories a day,” says Prof Leeds. By law, any formula diet designed as a total meal replacement must contain the recommended amount of nutrients for good health. However, this doesn’t apply to the type of meal replacements you use alongside food, so it’s important to know the difference. Formula diets aren’t suitable for everyone, including pregnant and breastfeeding women. So, if you’re going on a diet of 800 calories or fewer, consult a GP. Seek advice first if you’re diabetic. To stick to the plan, you need to like the products on offer and, of course, there’s the cost. Plus, once you’ve finished your liquid diet, it’s important not to revert back to the fry-ups and biscuits!