Mono Unsaturated Fatty Acids in Obesity - Weight Maintenance and Prevention of Lifestyle Diseases in Obese Subjects.
Condition: Overweight; Obesity
MeSH terms: Obesity; Overweight
Study type: Interventional

Summary: 
      The purpose of this study is to investigate the effect of three diets different in type and
      amount of fat in weight maintenance and prevention of life-style diseases in obese subjects.
    

Detailed description: 
      The obesity epidemic has raised concerns, because of complications such as type 2 diabetes,
      cardiovascular disease and certain types of cancer. Much conflict and confusion about the
      optimal diet for weight control exists among the public.

      The current dietary recommendations aim at reducing the total fat in the diet to less than
      30% of calories, increasing carbohydrates to 55-60%, and protein from lean meat and dairy
      products to 15-20%, and to keep the intake of sugar sweetened soft-drinks limited. There is
      good evidence from meta-analyses of intervention studies that a low fat diet can prevent
      weight gain in normal weight individuals, induce a small but clinically relevant weight loss
      in overweight individuals, and also reduce the risk of cardiovascular disease and type 2
      diabetes.

      However this recommended diet may not be of the optimal composition in preventing the
      progressive increase in obesity and lifestyle diseases. The traditional dietary
      recommendation has been challenged by the epidemiologist Walter Willett, Harvard Medical
      School in Boston. He claims that dietary fat is less important for the development of
      obesity, and that the fat content of the diet can be 40-45% of the energy providing from
      mainly mono- and polyunsaturated fatty acids. Based on mainly large-scale observational
      studies ('Nurses Health Study') he has developed new dietary guidelines, expressed as a new
      diet pyramid. In contrast to the current guidelines, more plant oils and plant foods, limited
      animal products, such as meat and dairy products (even lean products), and increased intake
      of olive oil, nuts, etc., e.g. guidelines closer to the "Mediterranean Diet".

      There is circumstantial evidence to support that this moderate fat, MUFA-rich diet will have
      a beneficial effect on some of the traditional risk factors for cardiovascular disease and
      type-2 diabetes. However, there is also growing concern that the increased total fat content
      will lead to weight gain and increased risk of obesity, and secondary to this, type-2
      diabetes and cardiovascular disease. This debate has now been taken up by some of the finest
      scientific journals. To test this hypothesis the largest and longest dietary intervention
      trial in Denmark is carried out at the Department of Human Nutrition.

      The objective is to identify the diet and diet components most effective for protection
      against weight gain, weight regain and prevention of life-style diseases in obese subjects.
      The three diets tested are according to:

        1. Willetts new dietary recommendations. High in mono unsaturated fat and low in glycemic
           index (50 subjects).

        2. The traditional dietary recommendations. Low in fat and medium in glycemic index (50
           subjects).

        3. The average Danish diet (Control). High in fat and high in glycemic index (25 subjects).

      The diets are ad libitum (i.e. no restriction in calorie intake), but very strict in dietary
      composition.
    

Intervention name(s): Mono Unsaturated Fatty Acids in Obesity
Intervention type(s): Behavioral
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: Dietary intervention; High-carbohydrate diet; High-fat diet; Moderate-fat diet; Obesity; Weight maintenance; Body composition; Glucose metabolism; Cardiovascular disease; Appetite regulation; Energy expenditure