Background The cross-sectional association between obesity and a lower health-related quality of life (HRQL) is clear. However, less is known about the association between changes in weight and HRQL. We examined the association between weight changes and changes in HRQL in a population-based sample of 2005 men and 2130 women aged 26–70 years.

Methods Weight was measured two or three times with 5-year intervals between 1995 and 2009, and was categorised as stable (change ≤2 kg, 40%), weight loss (19%), or weight gain 2.1–4.0 kg, 4.1–6.0 kg, or >6 kg (41%). Changes in HRQL (SF36 questionnaire, including physical and mental scales) per weight change category were compared with a stable weight using generalised estimating equations.

Results Weight gain was associated with declines of up to 5 points on five mainly physical scales and holds for different age categories. Especially for women, a dose-response relationship was observed, that is, larger weight gain was associated with larger declines in HRQL. Changes in HRQL for those with weight loss were small, but particularly on the mental scales, changes were in the negative direction compared to a stable weight.

Conclusions Weight gain and weight loss were associated with unfavourable changes in HRQL compared with a stable weight. For weight gain, this was most pronounced on the physical scales and for weight loss, although less consistent, on the mental scales.