Weight regain support works, but only by 1.56 kg a year

Losing weight is only half the problem; keeping it off is where most efforts founder, and regain after successful loss is common enough that maintenance deserves its own evidence base separate from weight loss itself. This review asked a precise question: for obese adults who have already lost at least 5% of their body weight without surgery, what actually helps them hold the line over the following year or more? The answer matters for anyone budgeting effort, money or medication toward keeping lost weight lost, because the honest size of the benefit shapes realistic expectations.

The reviewers searched Medline, PsycINFO, Embase and the Cochrane trials register through to January 2014 for randomised trials of maintenance interventions given to adults aged 18 or over who had lost at least 5% of body weight, with follow-up of weight change lasting 12 months or longer. Studies were screened independently and in duplicate, characteristics and outcomes were extracted, and results were pooled as mean differences in weight change. Forty-five trials involving 7788 individuals were included, covering behavioural programmes and the drug orlistat combined with behavioural support.

Behavioural interventions addressing both food intake and physical activity reduced weight regain by an average of 1.56 kg versus controls at 12 months, drawn from 25 comparisons involving 2949 participants. Orlistat combined with behavioural support produced a 1.80 kg difference against placebo across eight comparisons and 1738 participants, with a clear dose-response: 120 mg three times a day gave a 2.34 kg benefit while 60 mg and 30 mg doses gave a non-significant 0.70 kg. Every orlistat study reported more gastrointestinal adverse events than placebo. The overall verdict was small but significant benefits.

The finding confirms what maintenance researchers have long suspected: the interventions work, but the margins are slim, and a mean difference of under two kilograms at a year is meaningful at population scale while feeling modest to any individual. The search closed in January 2014, before the current generation of weight loss drugs arrived, so the modern maintenance toolkit looks different. What endures is that structured support addressing both diet and activity produced measurable protection against regain, and that regain is the default these programmes push against.

If you have lost weight and are fighting to keep it off, this is a reason to size expectations honestly: even structured, trial-grade support shifted the scale by roughly a kilo and a half over a year compared with going without it. That reframes maintenance as a game of small margins sustained over time rather than a problem any single programme solves outright. It is also a reason not to read some regain as personal failure, since the pooled evidence shows its pull is strong even inside well-run trials.