Measuring Outcomes in Adult Weight Loss Studies That Include Diet and Physical Activity: A Systematic Review

Table 2

Outcome data from the included studies: weight or BMI, body fat (BF) % or fat mass (FM), summary of weight or BMI and body fat measures, and attrition.

Study (reference number)	Baseline average weight (kg) ± SD and/or BMI (kg/m^2) ± SD (range)	Baseline average % fat and/or fat mass (kg) ± SD (range)	Follow-up average weight (kg) ± SD and/or BMI (kg/m^2) ± SD (range)	Follow-up average % fat and/or fat mass (kg) ± SD (range)	Average weight (kg) ± SD and/or BMI (kg/m^2) change ± SD (range)	Average % fat or fat mass (kg) change ± SD (range or CI)	Summary/agreement of measures	Attrition (if reported)
[27]	Weight: 83.6 ± 8.6; BMI: 31.4 ± 3.7	% BF: 46.9 ± 3.6; FM: 39.3 ± 6.1	Not reported	% BF: 41.9 ± 4.3	Weight loss: −8.3 ± 3.1	% BF: −5.0 ± 3.9; FM: −7.4 ± 3.7	Weight and fat measures decreased significantly. Weight loss mostly accounted for by FM.
[28]	Weight: 79.8 ± 11.8; BMI: 29.1 ± 4.8	% BF: 39.3 ± 7.5	Weight: 62.5 ± 8.3; BMI: ±24 ± 3.5	% BF: 29.3 ± 7.0	Weight loss: −17.3 (CI: 15.7–18.9); (=−22%); BMI: −5.1 (CI: −3.8–−6.4); (=−17.5%)	% BF: −10.0 (CI: 9–11)	All weight or BMI and fat measures decreased significantly.
[29]	Weight: 87.2 ± 12.6; BMI: 29.3 ± 1.6	% BF: 35.5 ± 6.0	Not reported	Not reported	Weight loss: −6.1 ± 0.6 (=−7.1%)	FM: −5.9 ± 0.6	Weight and fat measures decreased significantly. Weight loss mostly accounted for by FM.	20%
[30]	Weight: 96.4 ± 16.0; BMI: 36.4 ± 5.5	% BF: 46.2 ± 5.6; FM: 45.8 ± 12.3	Weight: 88.6 ± 15.7; BMI: 33.6 ± 5.3	% BF: 44.5 ± 6.1; FM: 39.6 ± 11.8	Weight loss: −7.8 ± 15.9; BMI: −2.8 ± 5.4	% BF: −2.4 ± 5.8; FM: −3.6 ± 12.0	Weight or BMI and fat measures decreased significantly.	25%
[31]	Weight: 76.9 ± 6.6; BMI: 28.5 ± 1.5	% BF: ±44.1 ± 3.8; FM: 34.1 ± 5.0	Weight: 64.3 ± 6.1; BMI: 23.8 ± 1.1	% BF: 33.9 ± 4.5; FM: 22.0 ± 4.6	Weight loss: −12.5 ± 2.2; BMI: −4.7 ± 1.3	% BF: −10.2 ± 4.1; FM: −12.1 ± 4.8	Weight or BMI and fat measures decreased significantly. Weight loss mostly accounted for by FM.
[32]	Weight: 103.5 ± 14.4; BMI: 36.1 ± 3.5	FM: 40.4 ± 7.8	Not reported	Not reported	Weight loss: −7.4 (CI: −9.1–−5.6)	FM: −3.8 (−5.0–−2.6)	Weight and fat measures decreased (not noted whether differences were significant).	32%
[33] (aerobic treatment arm)	Weight: 96.0 ± 23.0	FM: 38.4 ± 12.5	Weight: 86.4 ± 19.8	FM: 31.2 ± 11.0	Weight loss: −9.6 ± 4.5	FM: −7.2 ± 3.0	Weight or BMI and fat measures decreased significantly. Weight loss mostly accounted for by FM.
[34]	Weight: 104.5 ± 5.5; BMI: 39.5 ± 7.0	FM: 44.0 ± 2.5	Weight: 97.0 ± 3.5	FM: 36.0 ± 2.0	Weight loss: −7.5 ± 4.5	FM: −8.0 ± 2.2 (=−17.2%)	Weight or BMI and fat measures decreased significantly. Weight loss mostly accounted for by FM.
[35]	Weight: 87.7 ± 22.6; BMI: 32.2 ± 7.8	% BF: 38.4 ± 6.0	Weight: 74.8 ± 21.4	% BF: 30.3 ± 7.1	Weight loss: −8.2 ± 0.7	% BF: −8.1 ± 6.5	Weight and fat measures decreased significantly. Weight loss mostly accounted for by FM (91% loss was fat).	28%
[36]	Weight: 81.9 ± 10.5; BMI: 27.5 ± 1.6	% BF: 32.6 ± 7.6	Not reported	Not reported	Weight loss: −8.0 ± 2.0 (=−10.0%)	% BF: −25% change in % BF ± 3	Weight and fat measures decreased significantly.	4%
[37]	Weight: 100.2	% BF: 45.0%	Weight: 92.6	% BF: 41.8	Weight loss: −7.6	% BF: −3.2	Weight and fat measures decreased significantly. Diet and PA group lost significantly more fat and significantly less fat-free mass than non-PA subjects.
[38]	BMI: 30.5 ± 3	% BF: 43.9 ± 1.1	Not reported	% BF: 38.5 ± 1.3	Weight loss: −8.6 ± 0.9	% BF: −4.5%; FM: −7.0 ± 0.6	Diet + PA group lost significantly more weight than non-PA group; diet + PA group had significantly greater decrease in % BF than non-PA group. PA: 86% of weight loss from fat versus 73% f/non-PA group	20%
[39]	Weight: 85.2 kg ± 2.1; BMI: 31.6 ± 0.6	% BF: 40.2 ± 0.7; FM: 34.5 ± 1.3	Not reported	Not reported	Weight loss: −4.3 ± 0.7; BMI decrease: −1.8 ± 0.3	% BF: −1.3 ± 0.2; FM: −1.7 ± 0.5	Weight or BMI and fat measures decreased significantly. Fat loss more significant than weight loss.	10% at halfway point of study
[40]	Weight: 90.4 ± 2.9; BMI: 32.4 ± 1.3	% BF: 41.6 ± 1.5; FM: 38.0 ± 2.9	Not reported	Not reported	Weight loss: −9.1 ± 1.1	FM: −7.8 ± 0.82	Weight and fat measures decreased significantly. Weight loss mostly accounted for by FM: percentage of weight lost as fat significantly different for diet + PA group (88.6 ± 5.1%), versus diet only group (77.1 ± 4.0%).
[41]	Weight: 95.7 ± 16.6; BMI: 35.3 ± 5.7	FM: 39.3 ± 10	Not reported	Not reported	Weight loss: −5.4 (−7.0–3.0)	% BF: −1.9% (−2.6–−1.3); FM: −3.3 (−4.0–−2.0)	Weight and fat measures decreased significantly.	33%
[42]	Weight: 94.3 kg ± 16.0; BMI: 35.7 ± 6.0	% BF: 45.1 ± 4.2; FM: 40.0 ± 9.7	Weight: 90.1 ± 15.6	% BF: 43.2 ± 4.7; FM: 36.6 ± 9.2	Weight loss: −4.2 ± 15.8	% BF: −1.9 ± 4.5; FM: −3.4 ± 9.5	Weight and fat measures decreased significantly. Weight loss mostly accounted for by FM.	35%
[43]	Weight: 96.5 ± 20.2; BMI: 35.3 ± 6.5	% BF: 41.9 ± 9.4; FM: 40.3 ± 12.8	Weight: 93.3 ± 21.2; BMI: 34.2 ± 6.6	% BF: 41.2 ± 8.9; FM: 38.6 ± 12.6	Weight loss: −2.9 ± 20.7; BMI: −1.1 ± 6.5	% BF: −0.7 ± 9.2; FM: −0.9 ± 12.7 (=−2.3%)	Weight decreased significantly; body FM was “borderline significant” ( = 0.053). BMI and % BF declined more in intervention group than control, no significant differences between groups.
[44] (diet + aerobic ex.)	Not reported	Not reported	Not reported	Not reported	Weight loss: −6.8	% BF: −8.0	Weight and fat measures decreased significantly.
[44] (diet + aerobic + strength)	Not reported	Not reported	Not reported	Not reported	Weight loss: −7.0	% BF: −4.3	Results same as above. Weight loss through diet was not altered by aerobic or aerobic + strength training, but diet + PA increased muscle during weight loss.
[45]	Weight: 89.2 ± 12.0; BMI: 33.1 ± 4.0	% BF: 44.1 ± 4.0; FM: 36.8 ± 8.0	Weight: 86.1 ± 11.0; BMI: 32.0 ± 4.0	% BF: 43.1 ± 5.0; FM: 34.5 ± 7.0	Weight loss: −3.1 ± 11.5; BMI: −1.1 ± 4.0	% BF: −1.0 ± 4.5; FM: −2.3 ± 7.5	Weight or BMI and fat measures decreased significantly. Weight loss mostly accounted for by FM.
[46]	Weight: 82.9 ± 3.6; BMI: 30.8 ± 1.5	FM: 38.6 ± 2.9	Weight: 74.7 ± 3.3	FM: 31.4 ± 2.6	Weight loss: −8.2 ± 3.4	FM: −7.2 ± 0.7	Weight or BMI and fat measures decreased significantly. Weight loss mostly accounted for by FM. More fat loss associated with high protein diet + PA
[47]	Weight: 106.0 ± 25.6	% BF: 44.4 ± 5.6; FM: 47.6 ± 15.2	Weight: 90.7 ± 21.6	% BF: 35.3 ± 7.3; FM: 32.7 ± 12.7	Weight loss: −15.3 ± 1.1	% BF: −9.1 ± 0.5; FM: −14.9 ± 0.8	Weight and fat measures decreased significantly. Weight loss mostly accounted for by FM.
[48]	Weight: 88.8 ± 3.3; BMI: 31.8 ± 0.7	% BF: 45.1 ± 1.3; FM: 40.2 ± 2.1	Weight: 81.7 ± 2.9; BMI: 28.0 ± 1.5	% BF: 39.7 ± 1.6; FM: 32.6 ± 1.9	Weight loss: −7.1 ± 3.1 (=−8%); BMI: −3.8 ± 1.1 (=−12%)	% BF: −5.4 ±; 1.4; FM: −7.6 ± 2.0	Weight and fat measures decreased significantly. Weight loss mostly accounted for by FM. Diet + PA group lost more fat than PA only group.	48.8% in diet + PA group
[49]	Weight: 86.5 ± 12.0; BMI: 32.5 ± 5.0	FM: 42.0 ± 1.1	Not reported	FM: 36.8 ± 1.1	Weight loss: −7.6 ± 0.4	FM: −5.1 ± 0.5	Weight and fat measures decreased significantly. Weight loss mostly accounted for by FM.	16%
[50]	Weight: 92.1 ± 8.8	% BF: 44.0 ± 3.2	Not reported	Not reported	Weight loss: −10.5 ± 3.3	FM: −8.8 ± 2.1	Weight and fat measures decreased significantly. Weight loss mostly accounted for by FM.	25%
[51]	Weight: 78.1 ± 10.3	FM: 31.9 ± 6.2	Not reported	Not reported	Weight loss: −10.3 ± 3.0	FM: −9.6 ± 2.7	Weight and fat measures decreased significantly. Weight loss mostly accounted for by FM. Diet + PA group lost no lean tissue mass.	2.5%
[52]	Weight: 101.9 ± 11.2; BMI: 32.6 ± 2.5	% BF: 33.5 ± 4.2; FM: 34.2 ± 6.1	Weight: 86.7 ± 9.3; BMI: 27.8 ± 2.5	% BF: 25.0 ± 5.0; FM: 21.7 ± 5.2	Weight loss: −15.2 ± 6.3; BMI: −4.8 ± 2.5	% BF: −8.5 ± 4.7; FM: −12.5 ± 5.6	Weight or BMI and fat measures decreased significantly. Weight loss mostly accounted for by FM.
[53]	Weight: 94.5 ± 11.7; BMI: 33.1 ± 3.4	Not reported	Not reported	Not reported	Weight loss: −6.6 ± 6.4; BMI: −2.3 ± 2.1	% BF: −4.0 ± 4.1	Weight or BMI and fat measures decreased significantly.	23%
[54]	Weight: 95.7 ± 18.0; BMI: 33.9 ± 5.3	Not reported	Not reported	Not reported	Weight loss: −6.5 (CI: −4.6–−8.4)	% BF: −2.8 (CI: −1.9–−3.9); FM: −4.8 (CI:−3.2–−6.3)	Weight or BMI and fat measures decreased significantly. Weight loss mostly accounted for by FM.	24–43% (different groups)

Note: outcome data are presented for the longest follow-up time available. CI: 95% confidence interval. When body weight or BMI and/or body composition outcome measures were not reported, the data were not imputed as long as the change measures were intact and reported; in those cases “not reported” is presented. Significance indicates differences compared to baseline values and to diet only/control group(s) when indicated.