Exercise for overweight or obesity

Abstract

Background: Clinical trials have shown that exercise in adults with overweight or obesity can reduce bodyweight. There has been no quantitative systematic review of this in The Cochrane Library.

Objectives: To assess exercise as a means of achieving weight loss in people with overweight or obesity, using randomised controlled clinical trials.

Search strategy: Studies were obtained from computerised searches of multiple electronic bibliographic databases. The last search was conducted in January 2006.

Selection criteria: Studies were included if they were randomised controlled trials that examined body weight change using one or more physical activity intervention in adults with overweight or obesity at baseline and loss to follow-up of participants of less than 15%.

Data collection and analysis: Two authors independently assessed trial quality and extracted data.

Main results: The 43 studies included 3476 participants. Although significant heterogeneity in some of the main effects' analyses limited ability to pool effect sizes across some studies, a number of pooled effect sizes were calculated. When compared with no treatment, exercise resulted in small weight losses across studies. Exercise combined with diet resulted in a greater weight reduction than diet alone (WMD -1.1 kg; 95% confidence interval (CI) -1.5 to -0.6). Increasing exercise intensity increased the magnitude of weight loss (WMD -1.5 kg; 95% CI -2.3 to -0.7). There were significant differences in other outcome measures such as serum lipids, blood pressure and fasting plasma glucose. Exercise as a sole weight loss intervention resulted in significant reductions in diastolic blood pressure (WMD -2 mmHg; 95% CI -4 to -1), triglycerides (WMD -0.2 mmol/L; 95% CI -0.3 to -0.1) and fasting glucose (WMD -0.2 mmol/L; 95% CI -0.3 to -0.1). Higher intensity exercise resulted in greater reduction in fasting serum glucose than lower intensity exercise (WMD -0.3 mmol/L; 95% CI -0.5 to -0.2). No data were identified on adverse events, quality of life, morbidity, costs or on mortality.

Authors' conclusions: The results of this review support the use of exercise as a weight loss intervention, particularly when combined with dietary change. Exercise is associated with improved cardiovascular disease risk factors even if no weight is lost.

Conflict of interest statement

None known.

Figures

1

Funnel plot.

1.1. Analysis

Comparison 1 Exercise versus no treatment control, Outcome 1 Weight change in kilograms.

1.2. Analysis

Comparison 1 Exercise versus no treatment control, Outcome 2 Change in body mass index (BMI).

1.3. Analysis

Comparison 1 Exercise versus no treatment control, Outcome 3 Change in systolic blood pressure (mmHg).

1.4. Analysis

Comparison 1 Exercise versus no treatment control, Outcome 4 Change in diastolic blood pressure (mmHg).

1.5. Analysis

Comparison 1 Exercise versus no treatment control, Outcome 5 Change in total serum cholesterol (mmol/l).

1.6. Analysis

Comparison 1 Exercise versus no treatment control, Outcome 6 Change in serum triglycerides (mmol/l).

1.7. Analysis

Comparison 1 Exercise versus no treatment control, Outcome 7 Change in serum HDL (mmol/l).

1.8. Analysis

Comparison 1 Exercise versus no treatment control, Outcome 8 Change in fasting serum glucose (mmol/l).

2.1. Analysis

Comparison 2 Exercise versus diet, Outcome 1 Weight change in kilograms.

2.2. Analysis

Comparison 2 Exercise versus diet, Outcome 2 Change in body mass index (BMI).

2.3. Analysis

Comparison 2 Exercise versus diet, Outcome 3 Change in systolic blood pressure (mmHg).

2.4. Analysis

Comparison 2 Exercise versus diet, Outcome 4 Change in diastolic blood pressure (mmHg).

2.5. Analysis

Comparison 2 Exercise versus diet, Outcome 5 Change in total serum cholesterol (mmol/l).

2.6. Analysis

Comparison 2 Exercise versus diet, Outcome 6 Change in serum triglycerides (mmol/l).

2.7. Analysis

Comparison 2 Exercise versus diet, Outcome 7 Change in serum HDL (mmol/l).

2.8. Analysis

Comparison 2 Exercise versus diet, Outcome 8 Change in fasting serum glucose (mmol/l).

3.1. Analysis

Comparison 3 Exercise + diet versus diet alone, Outcome 1 Weight change in kilograms.

3.2. Analysis

Comparison 3 Exercise + diet versus diet alone, Outcome 2 Change in body mass index (BMI).

3.3. Analysis

Comparison 3 Exercise + diet versus diet alone, Outcome 3 Change in systolic blood pressure (mmHg).

3.4. Analysis

Comparison 3 Exercise + diet versus diet alone, Outcome 4 Change in diastolic blood pressure (mmHg).

3.5. Analysis

Comparison 3 Exercise + diet versus diet alone, Outcome 5 Change in total serum cholesterol (mmol/l).

3.6. Analysis

Comparison 3 Exercise + diet versus diet alone, Outcome 6 Change in serum triglycerides (mmol/l).

3.7. Analysis

Comparison 3 Exercise + diet versus diet alone, Outcome 7 Change in serum HDL (mmol/l).

3.8. Analysis

Comparison 3 Exercise + diet versus diet alone, Outcome 8 Change in fasting serum glucose (mmol/l).

4.1. Analysis

Comparison 4 High versus low intensity exercise with dietary change, Outcome 1 Weight change in kilograms.

4.2. Analysis

Comparison 4 High versus low intensity exercise with dietary change, Outcome 2 Change in body mass index (BMI).

4.3. Analysis

Comparison 4 High versus low intensity exercise with dietary change, Outcome 3 Change in systolic blood pressure (mmHg).

4.4. Analysis

Comparison 4 High versus low intensity exercise with dietary change, Outcome 4 Change in diastolic blood pressure (mmHg).

4.5. Analysis

Comparison 4 High versus low intensity exercise with dietary change, Outcome 5 Change in serum cholesterol (mmol/l).

4.6. Analysis

Comparison 4 High versus low intensity exercise with dietary change, Outcome 6 Change in serum triglycerides (mmol/l).

4.7. Analysis

Comparison 4 High versus low intensity exercise with dietary change, Outcome 7 Change in serum HDL (mmol/l).

4.8. Analysis

Comparison 4 High versus low intensity exercise with dietary change, Outcome 8 Change in serum glucose (mmol/l).

5.1. Analysis

Comparison 5 High versus low intensity exercise without dietary change, Outcome 1 Weight change in kilograms.

5.2. Analysis

Comparison 5 High versus low intensity exercise without dietary change, Outcome 2 Change in systolic blood pressure (mmHg).

5.3. Analysis

Comparison 5 High versus low intensity exercise without dietary change, Outcome 3 Change in diastolic blood pressure.

5.4. Analysis

Comparison 5 High versus low intensity exercise without dietary change, Outcome 4 Change in serum triglycerides (mmol/l).

5.5. Analysis

Comparison 5 High versus low intensity exercise without dietary change, Outcome 5 Change in serum HDL (mmol/l).

5.6. Analysis

Comparison 5 High versus low intensity exercise without dietary change, Outcome 6 Change in serum glucose (mmol/l).