HOW THE DEGREE OF UNSATURATION OF DIETARY FATTY-ACIDS INFLUENCES THE GLUCOSE AND INSULIN RESPONSES TO DIFFERENT CARBOHYDRATES IN MIXED MEALS

The association of fats with carbohydrates results in a lower glucose response but the influence of the nature of the dietary fatty acids ha s not been investigated clearly. We examined the effect of the degree of dietary fatty acid unsaturation on the postprandial glucose and ins ulin responses to a mixed meal. Eight young normolipidemic men consume d four different meals in random order. The meals differed in the natu re of their oils and in the type of their main carbohydrates. The meal s contained either a high ratio of monounsaturated to polyunsaturated n-6 fatty acids (MUFA) or a low ratio (PUFA) and either potatoes or pa rboiled rice. Proteins and saturated and polyunsaturated n-3 fatty aci d contents were not different among meals. Blood samples were collecte d every 30 min for 3 h after the test meal. The glucose response was s ignificantly lower 30 min after the parboiled rice-PUFA meal than afte r parboiled rice-MUFA or potato-MUFA (P < 0.05) meals. The insulin res ponse was lower after parboiled rice-PUFA than after potato-MUFA (P < 0.05) meals. Similarly, an effect of fat appeared after 30 min. Glucos e responses (F = 1.4, P < 0.01) and insulin responses (F = 5.3, P < 0. 05) to both carbohydrates were significantly lower with dietary PUFA c ompared with dietary MUFA. In conclusion, the degree of dietary fatty acid unsaturation (18:1 compared with 18:2) may influence the glucose and insulin responses to mixed meals.