The Belly Fat Study: Nutritional Intervention to Improve Metabolic Health in Subjects With Increased Abdominal Adiposity
Condition: Abdominal Obesity; Liver Fat
MeSH terms: Obesity; Obesity, Abdominal
Study type: Interventional

Summary: 
      In the Belly Fat study, the effects of two different caloric-restricted diets on metabolic
      health will be examined in male and female subjects with increased abdominal adiposity (BMI
      >27 kg/m2). Metabolic health is defined as health of the primary metabolic organs the liver,
      gut and the adipose tissue, examined in a static state as well as after the application of a
      challenge test.

      The diets are equally caloric-restricted, but differ in nutrient composition. It is
      hypothesized that one of the two diets causes a larger improvement in organ health and
      reduction in liver fat.
    

Detailed description: 
      Rationale: It is known that in particular visceral fat (abdominal obesity) and fat deposition
      in non-adipose tissue such as the liver are important factors related to metabolic health,
      such as the degree of insulin resistance, dyslipidaemia and other well-established
      cardio-metabolic risk factors. The arise of pathological consequences of abdominal obesity
      are a result of a disturbance in the elegant interplay between metabolic organs, such as the
      liver, adipose tissue and gut. Several nutrients have demonstrated to exert positive or
      negative effects on the health and functioning of metabolic organs. A diet (whole dietary
      approach) can thus be a power tool to improve the health status of individuals with abdominal
      obesity by improving organ health.

      Objective: The primary objective of this study is to compare the effects of two different
      diets on the static metabolic health status as assessed by determination of organ health and,
      more specifically, of lipid accumulation in the liver. The application of a mixed meal
      challenge test will be used to gain insight in the dynamic metabolic health status. A
      secondary objective is to determine the reaction (brain activity) of individuals with
      abdominal obesity after visual and olfactory food-cues.

      Study design and intervention: Randomized, parallel design consisting of three groups:

        1. 40 subjects, 12-wk nutritional intervention based on dietary advice: diet with 30%
           caloric restriction and a Western style nutrient composition

        2. 40 subjects, 12-wk nutritional intervention based on dietary advice: diet with 30%
           caloric restriction with a nutrient composition aimed at improving organ health and
           reducing liver fat

        3. 30 subjects, control group, no nutritional intervention (optional: dietary advice at the
           end of the study period)

      Measurements on metabolic health will be conducted at baseline and after 12-wk intervention
      and include:

        -  MR imaging for determining body fat distribution

        -  MR spectroscopy for quantification of liver fat

        -  Blood sampling (plasma and PBMCs) before and several timepoints after mixed meal
           challenge

        -  Adipose tissue sampling before and after mixed meal challenge

        -  Vascular measurements before and after mixed meal challenge

        -  Urine and feces sampling

      Study population: Males and females, 40-70 yrs old, BMI > 27 kg/m2
    

Intervention name(s): Dietary advice, Western; Dietary advice, Targeted
Intervention type(s): Other; Other
Intervention description(s): Dietary advice, guided by professional dieticians. Caloric restricted (-30en%) diet with Western type nutrient composition (SFA, carbohydrates, sugars, fruit juice, meat, dairy); Dietary advice, guided by professional dieticians. Caloric restricted (-30en%) diet with nutrient composition aiming at an improvement in organ health and a reduction in liver fat (PUFA, fish, soy protein, whole grain)
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Keywords: Metabolic health; Phenotyping; Abdominal obesity; Abdominal adiposity; Liver fat; Belly fat