49 research outputs found
Diet, nutrition and the prevention of type 2 diabetes
Objectives: The overall objective of this study was to evaluate and provide evidence
and recommendations on current published literature about diet and lifestyle in the
prevention of type 2 diabetes.
Design: Epidemiological and experimental studies, focusing on nutritional
intervention in the prevention of type 2 diabetes are used to make disease-specific
recommendations. Long-term cohort studies are given the most weight as to strength
of evidence available.
Setting and subjects: Numerous clinical trials and cohort studies in low, middle and
high income countries are evaluated regarding recommendations for dietary
prevention of type 2 diabetes. These include, among others, the Finnish Diabetes
Prevention Study, US Diabetes Prevention Program, Da Qing Study; Pima Indian
Study; Iowa Women’s Health Study; and the study of the US Male Physicians.
Results: There is convincing evidence for a decreased risk of diabetes in adults who are
physically active and maintain a normal body mass index (BMI) throughout
adulthood, and in overweight adults with impaired glucose tolerance who lose weight
voluntarily. An increased risk for developing type 2 diabetes is associated with
overweight and obesity; abdominal obesity; physical inactivity; and maternal diabetes.
It is probable that a high intake of saturated fats and intrauterine growth retardation
also contribute to an increased risk, while non-starch polysaccharides are likely to be
associated with a decreased risk. From existing evidence it is also possible that omega-3 fatty acids, low glycaemic index foods and exclusive breastfeeding may play a
protective role, and that total fat intake and trans fatty acids may contribute to the risk.
However, insufficient evidence is currently available to provide convincing proof.
Conclusions: Based on the strength of available evidence regarding diet and lifestyle in the prevention of type 2 diabetes, it is recommended that a normal weight status in the lower BMI range (BMI 21–23) and regular physical activity be maintained throughout adulthood; abdominal obesity be prevented; and saturated fat intake be less than 7% of the total energy intake
Young, healthy males and females present cardiometabolic protection against the detrimental effects of a 7-day high-fat high-calorie diet
Purpose: High-fat, high-calorie (HFHC) diets have been used as a model to investigate lipid-induced insulin resistance. Short-term HFHC diets reduce insulin sensitivity in young healthy males, but to date, no study has directly compared males and females to elucidate sex-specific differences in the effects of a HFHC diet on functional metabolic and cardiovascular outcomes.
Methods: Eleven males (24 ± 4 years; BMI 23 ± 2 kg.m−2; V̇O2 peak 62.3 ± 8.7 ml.min−1.kg−1FFM) were matched to 10 females (25 ± 4 years; BMI 23 ± 2 kg.m−2; V̇O2 peak 58.2 ± 8.2 ml.min−1.kg−1FFM). Insulin sensitivity, measured via oral glucose tolerance test, metabolic flexibility, arterial stiffness, body composition and blood lipids and liver enzymes were measured before and after 7 days of a high-fat (65% energy) high-calorie (+ 50% kcal) diet.
Results: The HFHC diet did not change measures of insulin sensitivity, metabolic flexibility or arterial stiffness in either sex. There was a trend towards increased total body fat mass (kg) after the HFHC diet (+ 1.8% and + 2.3% for males and females, respectively; P = 0.056). In contrast to females, males had a significant increase in trunk to leg fat mass ratio (+ 5.1%; P = 0.005).
Conclusion: Lean, healthy young males and females appear to be protected from the negative cardio-metabolic effects of a 7-day HFHC diet. Future research should use a prolonged positive energy balance achieved via increased energy intake and reduced energy expenditure to exacerbate negative metabolic and cardiovascular functional outcomes to determine whether sex-specific differences exist under more metabolically challenging conditions