Comparison of the metabolic effects of milk-derived α-lactalbumin and amino acids mixture with equal composition in diet-induced obese mice

The effects of milk-derived whey protein α-lactalbumin (α-lac) and amino acid mixture with equal amino acid profile (AA) on weight loss and weight regain in a model of diet-induced obesity were compared. Obesity was induced in C57BL/6J mice with a high-fat diet. Energy restriction was performed for 50 days on casein (calcium 0.8%) and two different high-calcium (1.8%) whey protein-based (α-lac + Ca and AA + Ca) diets, after which the animals were fed with the same diets ad libitum for additional 50 days. The mice on α-lac and AA lost significantly more weight and body fat than mice on casein diet (P < 0.05). There was no difference between α-lac and AA diets. Ad libitum feeding after weight loss resulted in weight regain and fat accumulation in all groups. Our findings indicate that the anti-obesity effects of α-lac during energy restriction can be reproduced by amino acid mixture with equal amino acid profile.

► Milk-derived -lactalbumin exerts anti-obesity properties.
► We compare the effects of -lactalbumin to amino acid mixture with equal composition.
► Lactalbumin and amino acid mixture enhance weight and fat loss compared to casein.
► Lactalbumin and amino acid mixture show equal anti-obesity properties.
► The anti-obesity effects of -lactalbumin are mediated mainly via its amino acids.