Researchers assessed a commercial weight-loss programme called Itrim, which is offered in Sweden. The programme allows dieters to choose the amount of weight they wish to lose and the pace they want to lose it at, and adjusts the number of calories they should eat each day accordingly.
A total of 8,361 participants - all of whom enrolled on a one-year weight-loss programme - were assessed by Dr Erik Hemmingsson and colleagues at Sweden's Karolinska Institute. Of these, 3,773 decided to follow a very low-calorie diet for the first three months (consisting of just 500 calories per day), while the remaining 4,588 followed a standard low-calorie diet (1,200 to 1,500 calories per day). After the initial three-month period, participants were required to follow a diet and exercise maintenance programme.
Analysis revealed that people on the very low-calorie diet typically lost 14kg, with just 18 per cent of participants dropping out of the programme. In contrast, those on the standard low-calorie diet lost an average of just 9kg, with a 23 per cent dropout rate. This shows that those on the lowest-calorie diet were more likely to stick to their weight-loss programme and achieve good results.
The researchers also observed that older people tended to show much more perseverance than younger dieters. Under-40s were almost four-and-a-half times more likely to drop out than over-60s. When asked to comment on this finding, Dr Hemmingsson suggested that younger people may have time constraints associated with raising a family that could make it difficult to stick to a demanding weight-loss programme. Conversely, older people may be more motivated by health reasons.
The expert noted that sticking to a very low-calorie diet plan "takes a lot of hard work to keep the weight off long-term". However, he claimed: "Hunger is surprisingly not a problem after the first few days and compliance with the diet is very good, as reflected by the results."
So if you're working out how to get your summer body ready, why not try a very low-calorie diet plan? You may find it easier - and the results even more impressive - than you expect.