The efficacy of a high protein/low glycemic index diet intervention in non-obese patients with asthma

Abstract

EFFORT Asthma study is a randomized controlled trial designed to assess the effects of diet and exercise in non-obese, untrained patients with asthma. We here present results from a subgroup of participants in the diet and control group to assess the feasibility of a high protein and low glycemic index (GI) diet and the effects on body composition. Of the 149 subjects who were included in the study, 76 subjects (30 males) were randomized into either a diet group (n = 38) or a control group (n = 38) and included in the present analysis. The 8 week intervention consisted of a high protein and low GI diet whilst the control group continued habitual diet. Thirty-three patients in the diet and 34 in the control group completed the study. The diet group reduced their energy intake by ~20% and had high dietary compliance. Intake of fatty fish doubled and GI was reduced by 8.4 units. The diet group reduced their weight by 2.3 ± 2.2 kg vs. 0.5 ± 1.8 (p < 0.001), fat mass by 2.2 ± 2.0 kg vs. 0.3 ± 1.6 kg (p < 0.001) and preserved lean body mass (-0.02 ± 1.1 kg). The control group had no changes in body composition. The ad libitum high protein-low GI diet resulted in a greater loss of fat mass among non-obese patients with asthma. The subjects were satisfactory and highly compliant with the dietary regimen.