Changes in Plasma Lipids and Lipoproteins in Overweight Men during Weight Loss through Dieting as Compared with Exercise – New England Journal of Medicine
As compared with controls (n = 42), dieters (n = 42) had significant loss of total body weight (-7.8±0.9 kg [mean ±SE]), fat weight (-5.6±0.8 kg), and lean (nonfat) weight (-2.1±0.5 kg) (P<0.001 for each variable), and exercisers (n = 47) had significant loss of total body weight (-4.6±0.8 kg) and fat weight (-3.8±0.7 kg) (P<0.001 for both variables) but not lean weight (-0.7±0.4 kg). Fat-weight loss did not differ significantly between dieters and exercisers. All subjects were discouraged from altering their diet composition; however, dieters and exercisers had slight reductions in the percentage of kilojoules derived from fat.
A meta-analysis of the past 25 years of weight loss research using diet, exercise or diet plus exercise intervention – International Journal of Obesity
The data shows, however, that a 15-week diet or diet plus exercise program, produces a weight loss of about 11 kg, with a 6.6(+/-0.5) and 8.6(+/- 0.8) kg maintained loss after one year, respectively.
Exercise and Fat/Weight Loss 1 – Lyle McDonald
But the simple fact is that, for the average untrained individual, realistic amounts of activity are unlikely to have massive direct impacts on either body weight or body fat; the caloric expenditure simply isn’t significant enough to impact on anything. As well, changes in diet have the potential to make a much greater contribution to the creation of a caloric deficit; removing 500 or even 1000 calories per day from the diet can usually be achieved much more readily than adding the same amount of activity. At least in certain populations.
Exercise and Fat/Weight Loss 2 – Lyle McDonald
Certainly larger amounts of exercise can approach significance (and as folks become fitter, they can burn more calories with activity) but the idea that a little bit of exercise is going to have a massive impact on anything is fairly misguided.