Psychological changes following weight loss in overweight and obese adults: a prospective cohort study

Participation in weight loss programs is often associated with improved wellbeing alongside reduced cardio-metabolic risk. In contrast, population-based analyses have found no evidence of psychological benefits of weight loss, but this may be due to inclusion of healthy-weight individuals. We therefore examined cardio-metabolic and psychological changes following weight loss in a cohort of overweight/obese adults.

Data were from 1,979 overweight and obese adults (BMI ≥ 25 kg/m(2); age ≥ 50 y), free of long-standing illness or clinical depression at baseline, from the English Longitudinal Study of Ageing. Participants were grouped according to four-year weight change into those losing ≥ 5% weight, those gaining ≥ 5%, and those whose weight was stable within 5%. Logistic regression examined changes in depressed mood (eight-item Center for Epidemiologic Studies Depression score ≥ 4), low wellbeing (Satisfaction With Life Scale score <20), hypertension (systolic blood pressure ≥ 140 mmHg or anti-hypertensives), and high triglycerides (≥ 1.7 mmol/l), controlling for demographic variables, weight loss intention, and baseline characteristics.

The proportion of participants with depressed mood increased more in the weight loss than weight stable or weight gain groups (+289%, +86%, +62% respectively; odds ratio [OR] for weight loss vs. weight stable = 1.78 [95% CI 1.29-2.47]). The proportion with low wellbeing also increased more in the weight loss group (+31%, +22%, -4%), but the difference was not statistically significant (OR = 1.16 [0.81-1.66]). Hypertension and high triglyceride prevalence decreased in weight losers and increased in weight gainers (-28%, 4%, +18%; OR = 0.61 [0.45-0.83]; -47%, -13%, +5%; OR = 0.41 [0.28-0.60]). All effects persisted in analyses adjusting for illness and life stress during the weight loss period.

Weight loss over four years in initially healthy overweight/obese older adults was associated with reduction in cardio-metabolic risk but no psychological benefit, even when changes in health and life stresses were accounted for. These results highlight the need to investigate the emotional consequences of weight loss.