This uses it whenever they needs to lose weight

A 2011 study in the United Kingdom that investigated the effects of intermittent energy restriction (to approximately 2266kJ a day for two days) compared to continuous energy restriction (approximately 6276KkJ a day for seven days a week) over six months, in 107 young overweight or obese women. It reported that both diets were equally effective for weight loss, as well as other markers of good health.
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But there seemed to be potential difficulties in adherence. At the completion of the study, only 58% of the women in the intermittent fasting group planned to continue with the diet, compared to 85% of those in the energy-restricted group.

This study was one of the largest undertaken in this area so far and the few previous studies in the field have had a much smaller number of participants. Although these smaller studies have been conducted for shorter time periods, the UK study is also considered to be relatively short term.

Weight loss within the first six months is common with a lot of different types of diets. But research studies have shown that the majority of people put much of the weight back on within three to five years.
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