Low calorie soups and shakes should be recommended as an NHS treatment, according to researchers from the University of Oxford.
A study published in the BMJ revealed that people lost over three times more weight on the low calorie liquid diet compared to those who following standard dietary advice.
Those who followed the total diet replacement programmes also had a reduced risk of type 2 diabetes and heart disease.
Total diet replacement programmes, the kind used in Newcastle University’s DiRECT research, are used for a short time period. In this new Oxford study the period was 12 weeks.
Participants replace food with specially formulated drinks, such as flavoured shakes and soups, as well as the odd protein bar. Other food is then gradually reintroduced after eight weeks.
The intervention only works if a participants dietary habits change for good, so participants visited a trained counsellor every week for two years to help them avoid weight gain.
As shown in Professor Roy Taylor’s Newcastle diet, this diet plan can help people with type 2 diabetes go into remission.
At every stage of the Oxford study, those following the diet replacement plan lost weight. After one year they had lost an average of 10.7kg (1st, 10lb), compared with 3.1kg (0.5st) in the standard diet group.
Those with type 2 diabetes in the diet replacement group were able to significantly reduce their medication, and there were also notable improvements in blood pressure and cholesterol.
These plans are currently only available privately, although the researchers behind the study hope that NHS England will introduce the diets as part of widely available obesity treatment. NHS England is considering this strategy for type 2 diabetes.
“[This is an] effective intervention which GPs can confidently recommend, knowing that it leads to sustainable weight loss and lowers the risk of heart disease and diabetes,” said study author Professor Paul Aveyard, professor of behavioural medicine at the University of Oxford.
There is some concern however that long-term caloric restriction can lead to reduced resting metabolic rate (RMR), which is the number of calories the body burns in a day. This could mean that people may need to maintain a lower calorie diet in the long-term, lest they start to regain the lost weight. A lower RMR is also associated with lower energy levels, trouble keeping warm and reduced mental clarity.
Meanwhile, restricting carbs without focusing on calories provides a means of weight loss that may avoid these issues, and so, may be preferable for some people. For more information visit our Low Carb Program.