The Effect of Irregular Meal Pattern Providing Hypo-energetic Diet on Energy Expenditure and Metabolism
Condition: Metabolic Disturbance; Obesity
Study type: Interventional

Summary: 
      In this study we will compare the effect of two different meal patterns. Firstly,
      participants will consume a diet providing their estimated energy requirement for a 7 day
      standardisation period (6 meals per day). After a one day laboratory visit, this will be
      followed by a 14 day intervention period when participants will randomly follow a regular
      meal pattern (6 meals/d) or an irregular meal pattern (3-9 meals/d). Following a further
      laboratory visit day, they will then consume the previous standardisation diet for a further
      3 days. The energy intake provided will be calculated to provide less energy than subjects
      are using which may result in approximately 2kg of weight loss. Participants will attend a
      screening visit in which they will complete questionnaires on medical health, eating habits
      and physical activity. In the laboratory visit, participants will be fasting and for 3 h
      after intake of a test drink, measurements will be taken of energy expenditure, fasting
      glucose, fasting gut hormones, fasting lipids and fasting insulin. A test meal will be
      offered. A questionnaire of subjective appetite ratings will be assessed while fasting, after
      the test drink, after the test meal, and during the intervention. Continuous interstitial
      glucose monitoring will be undertaken during the whole study period, Core body temperature
      will be measured before and after the intervention period. Also, wrist temperature will be
      measured during the whole study period.
    

Detailed description: 
      Experimental protocol:

      28 women who are a healthy weight or overweight (aged 18-45 years) will be recruited to a
      randomized parallel trial to follow one of two 14-d hypo-energetic diets. Firstly,
      participants will consume a diet providing their estimated energy requirement (6 meals/day)
      for a 7 day standardisation period. After a one day laboratory visit, this will be followed
      by a 14 day intervention period when participants will follow a regular meal pattern (6
      meals/d) or an irregular meal pattern (3-9 meals/d) (energy deficit of 800kcal/ 24h in both
      diets) (identical foods provided on both interventions whilst otherwise free living).
      Following a further laboratory visit day, they will then consume the previous standardisation
      diet providing their estimated energy requirement (6 meals/day) for a further 3 days. All
      foods to be consumed during the study will be provided to free of charge. These will comprise
      foods commonly consumed in the British diet and will be consumed in amounts designed to
      provide 800kcal/24h less than estimated energy requirements in the intervention period.
      Participants will attend the laboratory visits fasting and a blood sample will be obtained
      for fasting glucose, insulin and lipids. A test drink will then be given and over the
      following three hours measurements will be taken of energy expenditure (TEF). An ad libitum
      pasta test meal will be offered three hours after the test drink has been given. Subjective
      appetite ratings will be assessed while fasting, after the test drink, after the ad libitum
      meal, and during the intervention. Continuous interstitial glucose monitoring will be
      undertaken throughout the study. Ambulatory activity pattern measurement will be assessed in
      the intervention period. Core body temperature will be measured during the last 3 days of the
      first standardisation period, and during the final three standardisation days. Peripheral
      body temperature will be measured throughout the study period using a small i- button secured
      to the wrist. The study will commence at the early phase of the menstrual cycle (days1-7). A
      constant sleep-wake (and light exposure) routine will be followed for the whole study period
      which will be assessed by a written questionnaire form
    

Intervention name(s): Regular meal pattern; Irregular meal pattern
Intervention type(s): Other; Other
Intervention description(s): 6 meals every day; It consists of consuming a different number of meals every day (between 3 and 9).
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Prevention