Association of Healthy Lifestyle Factors and Obesity-Related Diseases in Adults in the UK.

Importance: A healthy lifestyle is associated with a reduced risk of cardiovascular disease in adults with obesity. Little is known about the associations between a healthy lifestyle and the risk of other obesity-attributable diseases in this population.

Objective: To examine the association between healthy lifestyle factors and the incidence of major obesity-related diseases in adults with obesity compared with those with normal weight.

Design, Setting, and Participants: This cohort study evaluated UK Biobank participants aged 40 to 73 years and free of major obesity-attributable disease at baseline. Participants were enrolled from 2006 to 2010 and prospectively followed up for disease diagnosis.

Exposures: A healthy lifestyle score was constructed using information on not smoking, exercising regularly, no or moderate alcohol consumption, and eating a healthy diet. For each lifestyle factor, participants scored 1 if they met the criterion for a healthy lifestyle and 0 otherwise.

Main Outcomes and Measures: The risk of outcomes according to the healthy lifestyle score in adults with obesity compared with those with normal weight were examined using multivariable Cox proportional hazards models with Bonferroni correction for multiple testing. The data analysis was performed between December 1, 2021, and October 31, 2022.

Results: A total of 438 583 adult participants in the UK Biobank were evaluated (female, 55.1%; male, 44.9%; mean [SD] age, 56.5 [8.1] years), of whom 107 041 (24.4%) had obesity. During a mean (SD) follow-up of 12.8 (1.7) years, 150 454 participants (34.3%) developed at least 1 of the studied diseases. Compared with adults with obesity and 0 healthy lifestyle factors, individuals with obesity who met all 4 healthy lifestyle factors were at lower risk of hypertension (HR, 0.84; 95% CI, 0.78-0.90), ischemic heart disease (HR, 0.72; 95% CI, 0.65-0.80), arrhythmias (HR, 0.71; 95% 0.61-0.81), heart failure (HR, 0.65; 95% CI, 0.53-0.80), arteriosclerosis (HR, 0.19; 95% CI, 0.07-0.56), kidney failure (HR, 0.73; 95% CI, 0.63-0.85), gout (HR, 0.51; 95% CI, 0.38-0.69), sleep disorders (HR, 0.68; 95% CI, 0.56-0.83), and mood disorders (HR, 0.66; 95% CI, 0.56-0.78). The lifestyle profiles associated with the lowest risks included a healthy diet and at least 1 of the 2 healthy behaviors of physical activity and never smoking. Compared with adults with normal weight, those with obesity were at higher risk of several outcomes, irrespective of the lifestyle score (adjusted HRs ranged from 1.41 [95% CI, 1.27-1.56] for arrhythmias to 7.16 [95% CI, 6.36-8.05] for diabetes for adults with obesity and 4 healthy lifestyle factors).

Conclusion and Relevance: In this large cohort study, adherence to a healthy lifestyle was associated with reduced risk of a wide range of obesity-related diseases, but this association was modest in adults with obesity. The findings suggest that although a healthy lifestyle seems to be beneficial, it does not entirely offset the health risks associated with obesity.