A review and meta-analysis of the effect of weight loss on all-cause mortality risk

Abstract

Overweight and obesity are associated with increased morbidity and mortality, although the range of body weights that is optimal for health is controversial. It is less clear whether weight loss benefits longevity and hence whether weight reduction is justified as a prime goal for all individuals who are overweight (normally defined as BMI . 25 kg/m 2 ). The purpose of the present review was to examine the evidence base for recommending weight loss by diet and lifestyle change as a means of prolonging life. An electronic search identified twenty-six eligible prospective studies that monitored subsequent mortality risk following weight loss by lifestyle change, published up to 2008. Data were extracted and further analysed by meta-analysis, giving particular attention to the influence of confounders. Moderator variables such as reason for weight loss (intentional, unintentional), baseline health status (healthy, unhealthy), baseline BMI (normal, overweight, obese), method used to estimate weight loss (measured weight loss, reported weight loss) and whether models adjusted for physical activity (adjusted data, unadjusted data) were used to classify subgroups for separate analysis. Intentional weight loss per se had a neutral effect on all-cause mortality (relative risk (RR) 1·01; P ¼ 0·89), while weight loss which was unintentional or ill-defined was associated with excess risk of 22 to 39 %. Intentional weight loss had a small benefit for individuals classified as unhealthy (with obesity-related risk factors) (RR 0·87 (95 % CI 0·77, 0·99); P ¼ 0·028), especially unhealthy obese (RR 0·84 (95 % CI 0·73, 0·97); P ¼ 0·018), but appeared to be associated with slightly increased mortality for healthy individuals (RR 1·11 (95 % CI 1·00, 1·22); P ¼ 0·05), and for those who were overweight but not obese (RR 1·09 (95 % CI 1·02, 1·17); P ¼ 0·008). There was no evidence for weight loss conferring either benefit or risk among healthy obese. In conclusion, the available evidence does not support solely advising overweight or obese individuals who are otherwise healthy to lose weight as a means of prolonging life. Other aspects of a healthy lifestyle, especially exercise and dietary quality, should be considered. However, well-designed intervention studies are needed clearly to disentangle the influence of physical activity, diet strategy and body composition, in order to define appropriate advice to those populations that might be expected to benefit.

Obesity-Related Glomerulopathy

“…Reduced urinary protein excretion by weight loss intervention is expected to stabilize renal function (22). But unintentional weight loss is also reported as being associated with the progression of renal diseases (23), which might reflect nutritional deficit being related to disease progression (24). In our study, we aimed to observe the effect of weight loss intervention in the renal function of patients with overt ORG, but failed to find a correlation between weight changes and changes in eGFR.…”

Anorexia, undernutrition, weight loss, sarcopenia, and cachexia of aging

“…Some studies demonstrated increased mortality even after intentional weight loss in older people; it is difficult to determine what proportion of weight loss labeled intentional was instead unintentional [50]. Harrington et al analyzed 26 studies examining the connection between weight loss and mortality and demonstrated that weight loss that was unintentional or ill defined was associated with a significant (22-39 %) increase in mortality, whereas intentional weight loss had no significant effect on mortality [32].…”

Technology-Assisted Weight Loss Interventions in Primary Care: A Systematic Review

“…12 Weight loss, even when modest (≥ 5 %), is associated with significant improvement in cardiovascular disease (CVD) risk factors, 13 quality of life, 14 and all-cause mortality for those with comorbidities. [15][16][17][18] Intensive, tailored lifestyle modification programs result in significant weight loss, health benefits, [19][20][21] and perhaps cost savings. 22 Those who receive advice from their PC provider (PCP) to lose weight are more likely to do so, 23 yet existing programs are challenged by high attrition rates, weight regain, resource-intensive requirements, and poor scalability.…”