Changes in Nutritional Pattern, Insulin Sensitivity and Glucose Tolerance During Weight Loss in Obese Patients from a Mediterranean Area

Abstract

In order to study the nutritional pattern in obese subjects living in an area with a Mediterranean diet, as well as the modifications in nutritional behaviour, cardiovascular risk factors and insulin sensitivity induced by changes in nutritional pattern, 54 obese patients completed a 20-week behaviour programme. They prospectively fulfilled a food records diary in order to ascertain their nutritional pattern. Weight, body mass index (BMI). waist-to-hip ratio (WHR), blood pressure (BP), cholesterol, HDL-c, LDL-c, triglycerides, fasting and 2 h-post glucose load plasma glucose were determined at the onset and at the end of the study. Insulin sensitivity index (SI), and glucose effectiveness (Sg) were assessed by using the modified FSIVGTT. The usual diet in obese patients living in a Mediterranean country is low in carbohydrates (35%) and high in fats (43%), 55% of the latter being monounsaturated fatty acids (MUFAs), especially olive oil. After the educational programme they decreased the caloric intake to slightly over 700 Kcal/day, with a reduction of 36% in carbohydrates consumption, 18% in proteins and 43% in fats (46% in MUFAs). These modifications resulted in a decrease in weight, BMI, WHR, BP, and fasting and 2 h-post glucose load plasma glucose (all p < 0.05), whereas the lipoprotein profile did not change. In a similar way SI and Kg (glucose disappearance rate) increased, while fasting plasma insulin (FPI) decreased (p < 0.05) and Sg and I1+3 remained unaffected. Our results indicate that weight loss induced by caloric restriction improves insulin sensitivity rather insulin secretory capacity or glucose effectiveness, and all the cardiovascular risk factors but lipoproteic profile, that remains unchanged, probably because of the lower MUFAs consumption. These facts should be taken into account when recommending changes in the diet of obese patients with a Mediterranean-style diet.

Diabetes Nutrition and Complications Trial

“…These trends are associated with favorable changes in diabetes metabolic control parameters. Likewise these changes in monounsaturated fatty acids-tosaturated fatty acids and polyunsaturated fatty acids-to-saturated fatty acids ratios have been associated to salutary cardiovascular changes (13)(14)(15)(16).…”

Metabolic syndrome

“…Unlike the WHO criteria, these criteria do not include a glucose tolerance test, which would increase workload in primary care. Patients and primary care teams should focus on preventing all components of metabolic syndrome, bearing in mind that the risk of developing the metabolic syndrome increases with weight gain9 and insulin insensitivity is improved by weight loss,10 and eating less saturated fat 11. Earlier this month in its report Preventing chronic diseases: a vital investment , WHO published its latest projections on increased premature deaths from chronic diseases, including diabetes, and called for urgent action on modifiable risk factors such as unhealthy diets and physical inactivity.…”

Improved Cardiovascular Parameter With a Nutrient-Dense, Plant-Rich Diet-Style: A Patient Survey With Illustrative Cases

“…More olive oil in the diet is associated with more weight gain and obesity. 31 Even back in 1965, a study demonstrated that heart patients given olive oil and corn oil had a higher risk of heart attack and death rate than the control, lower-fat diet. 32 Modern studies are inconsistent, confounded by replacement foods, but some have confirmed that more of these (omega-6) oils in the diet are associated with higher mortality from heart disease.…”