Systematic review of long-term weight loss studies in obese adults: clinical significance and applicability to clinical practice

Abstract

BACKGROUND: Obesity is a common health problem that requires a long-term care approach. We systematically reviewed long-term (Z2 y) studies investigating dietary/lifestyle, pharmacologic, and surgical weight loss methods to assess (1) weight loss efficacy, defined by absolute weight loss and the proportion of subjects with Z5% weight loss, (2) effects of weight loss on cardiovascular risk factors, and (3) applicability of findings from studies to everyday clinical practice. METHODS: The MEDLINE, HealthSTAR, and the Cochrane Controlled Trials databases were searched for studies investigating the long-term efficacy of weight loss methods in overweight and obese adults. Data were extracted for (i) weight loss after 1 y (pharmacologic studies only), 2 y, 3 y, and 4 y, (ii) proportion of subjects with Z5% weight loss at the end of follow-up, and (iii) changes (end-of follow-up minus baseline values) in blood lipids, fasting blood glucose, and systolic and diastolic blood pressure. RESULTS: Dietary/lifestyle therapy provides o5 kg weight loss after 2-4 y, pharmacologic therapy provides 5-10 kg weight loss after 1-2 y, and surgical therapy provides 25-75 kg weight loss after 2-4 y. Weight loss of Z5% baseline weight is not consistently associated with improvements in cardiovascular risk factors and these benefits appear to be intervention specific and occur mainly in people with concomitant cardiovascular risk factors. Weight loss studies have methodologic limitations that restrict the applicability of findings to unselected obese people assessed in everyday clinical practice. These limitations include an inadequate study duration, large proportions of subjects lost to follow-up, a lack of an appropriate usual care group, and a lack of reporting of outcomes in high-risk subgroups. CONCLUSIONS: Dietary/lifestyle and pharmacologic weight loss interventions provide modest weight loss, and may improve markers of cardiovascular risk factors although these benefits occur mainly in patients with cardiovascular risks. Studies investigating weight loss have methodologic limitations that restrict the applicability of findings to obese patients assessed in clinical practice.

Lifestyle Interventions for Adults With Serious Mental Illness: A Systematic Literature Review

“…The mean weight loss for the three single-group studies (20,31,24) was 8.2±5 pounds, whereas the three quasi-experimental studies (24,25,28) and four randomized controlled trials (21–23,35) showed more modest average weight loss (6.2±.4 pounds and 3.4±2.9 pounds, respectively). The mean for the randomized controlled trials reviewed falls below the mean weight loss reported in meta-analyses of randomized controlled trials of lifestyle interventions tested in the general population, which was eight to 11 pounds (44,45). The difference in weight loss outcomes between the general population and persons with serious mental illness may be due to variability in treatment intensity, worse health status at baseline among persons with serious mental illness, or methodological differences across studies.…”

Obesity dilemma in the global burden of cardiovascular diseases

“…Despite numerous observed landmarks on clinical existence of the obesity paradox, one must not disregard that lifestyle modifications and obesity treatment must be the mainstay of therapeutic measures in order to improve outcomes from the cardiovascular disease continuum (25)(26)(27)(28). Treatment of obesity is connected with multiple health benefits, particularly the common risk factors as diabetes, chronic renal disease, hypertension and related to the decrease in total or cardiovascular mortality (17,29,30).…”

Medical Therapy for Obesity

“…In another systematic review of 16 studies that used diet but without pharmacological intervention, and that had >100 subjects in each group and a duration of >1 year, weight loss after 2-3 years was usually <5 kg below baseline (3.5 ± 2.4 kg; range, 0.9-10.0 kg), and after 4-7 years where there were data, it was 3.6 kg ± 2.6 kg below baseline. 7 Portion-controlled diets are one way of achieving a balanced caloric deficit. This can be done most simply by using individually packaged foods.…”