Effects of Fat and Carbohydrates in Obese Men (FATFUNC)

Obesity has become a global epidemic, and treating and preventing obesity appears to be one of the world's greatest challenges. The disorder is associated with a wide range of metabolic and hormonal changes, including the development of insulin resistance, changes in adipose tissue function, increased levels of blood lipids, cardiovascular disease and obesity induced fatty liver. Obesity is characterized by inflammation in adipose tissue, altered fat storage capacity and increased exchange of lipids between adipose tissue and blood, and increased secretion of cytokines from adipose tissue. Cytokines are believed to play a central role in the regulation of adipose tissue, the size of adipocytes and other metabolic conditions. The hepatic synthesis of lipoproteins and interaction with adipose tissue is essential for the body's energy storages. The central role of the liver in energy supply, fat storage and normalization of blood values implies the importance of investigating the interaction between adipose tissue and liver to increase knowledge about the morbidity of obesity. Central obesity and insulin resistance are clear risk factors for the development of fatty liver, but the importance of diet is unclear. The common perception is that fatty liver condition can be improved by a reduction in dietary fat and cholesterols, but the relationship is unclear, and contradictory findings occur in epidemiological studies. It is therefore necessary to better understand the impact of the different macro-nutrients. The purpose of this study is to determine whether two weight reducing diets with equal calorie levels that contain high or low fat differentially affects the adipose tissue function, distribution of body fat, as well as tissue, blood and urine levels of inflammatory markers, lipids, vitamins, hormones and other substances that may be related to metabolically health.

Inclusion Criteria. Healthy men. BMI 30-40. Fasting blood glucose < 7 mM. Stable body weight last 2 months. Exclusion Criteria. High intake of alcohol. Medication affecting glucose or lipid metabolism. Allergy towards important food items in the diet. Inflammatory bowel disease. Surgery or use of antibiotics last 2 months.

Veum VL, Laupsa-Borge J, Eng O, Rostrup E, Larsen TH, Nordrehaug JE, Nygard OK, Sagen JV, Gudbrandsen OA, Dankel SN, Mellgren G. Visceral adiposity and metabolic syndrome after very high-fat and low-fat isocaloric diets: a randomized controlled trial. Am J Clin Nutr. 2017 Jan;105(1):85-99. doi: 10.3945/ajcn.115.123463. Epub 2016 Nov 30.