The Metabolic Syndrome of ω3-Depleted Rats. IX. Food Intake

ABSTRACT

The present study complements recent investigations on the changes in fatty acid content and pattern of liver phospholipids and triglycerides found in ω3-depleted rats which, when exposed for 2 weeks to a flaxseed oil-enriched diet, display aggravated liver steatosis, visceral obesity and excess body weight. In the present experiments, the ω3- depleted rats exposed to the flaxseed oil-enriched diet still displayed insulin resistance, with higher plasma glucose and insulin concentrations than in control animals undergoing the same dietary manipulations. The food intake and gain in body weight after the switch in diet were also higher in the ω3-depleted rats than in control animals exposed for the same period to either soybean or flaxseed oil-enriched diets, there being a close analogy between these two variables in the 3 groups of rats. Emphasis is placed on the orexigenic effect attributable to the brain accumulation of C22:5ω3 and C22:6ω3, on the flaxseed dietary self-selection in the ω3-depleted rats, and on the increase in the lipid content of the diet from 5 to 10% (w/w) as possible determinants of the increase in food intake. In a clinical perspective, these findings indicate that, when considering the most suitable dietary approach to correct a deficiency in long-chain polyunsaturated ω3 fatty acids, equal attention should be paid to the lipid and ω3 fatty acid content of the diet, as well as to food intake, in order to avoid undesirable increases in adipose tissue mass and body weight.

Keywords:

Long-chain polyunsaturated ω3 fatty acid-depleted rats, soya, sunflower and flaxseed oils, liver phospholipid, insulin resistance, food intake, body weight.