Evaluation of the use of esterified fatty acid oils enriched in medium-chain fatty acids in weight loss diets for dogs

Esterified fatty acid oils (EAOs) are obtained from esterification of vegetable acid oils with glycerol. These fat sources have the same fatty acid (FA) composition as their respective native oils but new chemical properties. Several studies have confirmed the potential of medium-chain fatty acids (MCFA) to reduce fat mass (FM) in humans and rodents. This study investigates the use of EAOs with different MCFA proportions on food preferences, digestibility and weight loss management in dogs. A basal diet was supplemented with 8% of three different fat sources: C0: soya bean-canola EAO, C20: soya bean-canola (80%) coconut (20%) EAO and C40: soya bean-canola (60%) coconut (40%) EAO. Food preference of these EAOs was tested using a two-pan preference test. Dogs presented a higher daily food intake of C20 and C40 compared to C0 (C20: 155 +/- 18.6g vs. C0: 17 +/- 7.0g, p<0.001; C40: 117 +/- 13.9g vs. C0: 28 +/- 10.5g, p<0.05 respectively). Also, the digestibility of the three experimental diets was tested. C20 and C40 showed higher ether extract, total FA and saturated FA digestibilities (p<0.05) than C0 diet. Lastly, the three diets were investigated in a 14-week weight loss study, following 16weeks of ad libitum feeding to induce overweight condition. Body weight (BW) reduction was lower (C0: 20.1 +/- 2.32%, C20: 14.6 +/- 1.43% and C40: 15.7 +/- 1.23%, p<0.05) and FM was higher (FM, 18.7 +/- 3.42%, 27.9 +/- 3.90% and 28.2 +/- 2.88% for C0, C20 and C40, respectively, p<0.05) for diets C20 and C40 than for C0. Feeding diets with MCFA at these inclusion levels to experimentally overweight dogs during 14weeks do not result in faster weight loss compared to unsaturated long-chain FA.