Macrophages can exhibit distinct phenotypes and functions in response to stimuli and can polarize into one of three distinct phenotypes: a pro-inflammatory (M1), an anti-inflammatory pro-tissue (M2) and metabolically-activated (MMe) macrophage phenotypes. Thirty-six healthy volunteers were recruited and randomized into one of three macronutrient intake groups (glucose, lipids, proteins). This study measured the effects of macronutrient intake on the macrophage differentiation.