How Often Should We Eat
Condition: Intermittent Fasting; Meal Frequency
Study type: Interventional

Summary: 
      The Danish Food Administration recommends eating three main meals and three small meals a day
      in order to maintain a healthy lifestyle. However, there is little research to support this
      concept- moreover, many studies shows that fasting can have a positive impact on our health.

      HYPOTHESIS AND PURPOSE The investigators hypothesize, that the number of meals per day in
      order to maintain a healthy lifestyle will not differ in normal weight subjects.

      The investigators will include 1) healthy, normal weight subjects. The investigators will
      study the effects of two daily meals.

      More specifically, the investigators want to better understand how the body reacts to
      long-term, intermittent fasting (14 h /day for 4 weeks). The investigators will assess
      cognitive function, dietary intake, appetite regulation, fitness, glucose and insulin
      responses, as well as fat and muscle composition of the body before, during, and after the
      study.

      Our long-term goals are to compare the effects of intermittent fasting with acute fasting.
      All of this is in an effort to establish how our eating habits ultimately affect our health
      and to, perhaps, contribute to new recommendations for healthy eating in normal weight
      population.

      BACKGROUND Obesity and diabetes are increasing health threats facing the Western world today,
      despite abundant research efforts and campaigns to prevent such outcomes. Throughout the
      years, as the incidence of both obesity and diabetes in the general population has increased,
      so too has the typical number of daily meals. A once common three meals per day has now
      increased to six meals per day, in many instances. Recent animal research has shown that
      intermittent fasting (one or two meals per day) over a long period of time can improve
      cardiovascular health and prevent chronic diseases. Biochemically, fasting leads to an
      activation of metabolic mechanisms designed to preserve carbohydrates and increase the
      dependence on energy produced by the metabolism of fat. There is little scientific evidence
      regarding the number of meals per day that proves to be the healthiest, and those studies
      that do exist have opposing conclusions. Several theories do exist regarding the number of
      meals per day that affect us in the most favorable way, but these are just theories. Our
      study is the first to assess, in both a systematic and controlled setting, how long-term,
      intermittent fasting affects the human body.
    


Intervention name(s): Intermittent fasting - the effect on glucose metabolism, body composition and cognitive function
Intervention type(s): Behavioral
Intervention description(s): Each of the 10 subjects must through a period of monitoring (four weeks) before the study period (four weeks). Before, during, and after both the monitoring period and the study period, the subjects will undergo tests at Rigshospitalet.
DAY 1: Inclusion and exclusion of subjects DAY 1 to DAY 28: Monitoring period (usual lifestyle)
28 days of dietary monitoring
28 days measurement by pedometer DAY 1, DAY 28 & DAY 56: Test 1
Oral glucose tolerance test with stable isotopes
Fat and muscle biopsies DAY 2, DAY 29 & DAY 57: Test 2
DXA scanning
Resting Metabolic Rate Measurement
VO2max test on bicycle
Cognitive testing
MRI of the brain and abdomen DAY 9, DAY 19, DAY 38 & DAY 48: Test 3
Actiheart for 3 days
72-hour blood glucose monitoring with CGMS System DAY 29 to DAY 57: INTERVENTION
Fasting from 7am - 9pm
28 days of dietary monitoring
28 days measurement by pedometer
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: Intermittent fasting; Meal frequency; body composition; cognitive function; glucose metabolism