Fatty acid (FA) composition is a determinant of the physiological effects of dietary oils. This study investigated the effects of vegetable oil supplementation with different FA compositions on anthropometric and biochemical parameters in obese women on a hypocaloric diet with lifestyle modifications. Seventy-five women (body mass index, BMI, 30⁻39.9kg/m²) were randomized based on 8-week oil supplementation into four experimental groups: the coconut oil group (CoG, n = 18), the safflower oil group (SafG, n = 19), the chia oil group (ChG, n = 19), and the soybean oil placebo group (PG, n = 19). Pre- and post-supplementation weight, anthropometric parameters, and body fat (%BF), and lean mass percentages (%LM) were evaluated, along with biochemical parameters related to lipid and glycidemic profiles. In the anthropometric evaluation, the CoG showed greater weight loss (Δ% = -8.54 ± 2.38), and reduced BMI (absolute variation, Δabs = -2.86 ± 0.79), waist circumference (Δabs = -6.61 ± 0.85), waist-to-height ratio (Δabs = -0.041 ± 0.006), conicity index (Δabs = -0.03 ± 0.016), and %BF (Δabs = -2.78 ± 0.46), but increased %LM (Δabs = 2.61 ± 1.40) (p < 0.001). Moreover, the CoG showed a higher reduction in biochemical parameters of glycemia (Δabs = -24.71 ± 8.13) and glycated hemoglobin (Δabs = -0.86 ± 0.28) (p < 0.001). The ChG showed a higher reduction in cholesterol (Δabs = -45.36 ± 0.94), low-density lipoprotein cholesterol (LDLc; Δabs = -42.53 ± 22.65), and triglycerides (Δabs = -49.74 ± 26.3), but an increase in high-density lipoprotein cholesterol (HDLc; abs = 3.73 ± 1.24, p = 0.007). Coconut oil had a more pronounced effect on abdominal adiposity and glycidic profile, whereas chia oil had a higher effect on improving the lipid profile. Indeed, supplementation with different fatty acid compositions resulted in specific responses.
Keywords: chia oil; coconut oil; dietary re-education; lipid and glycemic profile; obesity treatment; sunflower oil.