Effects of Re-Feeding Duration on Weight Maintenance After Weight Loss With Very-Low-Energy Diets (VLEDs)
Condition: Obesity
MeSH terms: Obesity
Study type: Interventional
Phase: Phase 4

Summary: 
      The primary objective of the study is to test the hypothesis that prolonged re-feeding after
      VLED induced weight loss improves weight maintenance and eating behaviour
    

Detailed description: 
      VLED program:

      During the initial 12 weeks, patients were encouraged to follow a strict liquid
      very-low-energy diet (470-820 kcal). They selected and paid themselves for one of the
      following commercially available diets; Modifast® (820 kcal), Nutrilett® (560 kcal) or
      Cambridgekuren® (470 kcal). Free consumption of non-caloric drinks (<6 kcal/100 g) was
      allowed. All patients had scheduled nurse visits at week 0 (baseline), 2, 5, 8, and 12. Body
      weight was registered at each visit and patients were given support and counselling to
      enhance VLED compliance. Side effects were monitored and a more frequent contact was offered
      if needed. All patients were encouraged to be physically active.

      Dietary treatment:

      Following VLED, dietary treatment advice was given during individual dietician counseling at
      nine study visits (week 12, 15, 18, 21, 26, 32, 38, 44, and 52). At week 12, the dietician
      assigned patients with ≥10% weight loss to treatment group according to randomization.
      Standardized written and oral instructions for one or six week re-feeding were provided;
      hence, participants as well as study staff were aware of group assignment. During re-feeding,
      ordinary meals were gradually re-introduced and VLED portions removed. Patients with one week
      re-feeding (Group 1) (instructed at week 12) started with breakfast for three days, added
      lunch (or dinner) the next four days, and thereafter the third meal was re-introduced and
      VLED discontinued. Patients with six week re-feeding (Group 6) (instructed at week 12, 15,
      and 18) started with one regular meal (patient's choice) for three weeks. A second meal was
      added the next three weeks, and at week eight the third meal was re-introduced and VLED
      discontinued. For both groups between-meal snacks (e.g. fruit) were recommended from the
      completion of the re-feeding periods.

      Recommended energy intake was based on an estimated energy requirement minus 30% to achieve
      an energy-reduced level. Energy requirement was calculated from the equation of
      Harris-Benedict for estimation of basal metabolic rate, adjusted by factor 1.3 for total
      energy expenditure (moderate level of physical activity). Recommended energy distribution for
      breakfast, lunch and dinner was 20, 35 and 35% of daily energy intake, and 10% from snacks.
      Dietary prescriptions followed the Swedish Nutrition Recommendations. All patients were
      encouraged to increase their level of physical activity.

      Power calculation and randomization:

      Sample size calculations were based on data from a similar study. A sample size of 75
      patients per treatment arm was derived, assuming 80% power to detect a 4 kg weight loss
      difference, SD 7 kg, statistical significance level P<0.05, and 35% dropout between week 12
      and 52.

      Two-hundred and sixty-nine patients started on the VLED regimen, and were after 12 weeks
      eligible for randomization if they had lost ≥10% of initial body weight. The randomization
      was stratified by the combination of sex and degree of weight loss (strictly greater than or
      less than 17.1% weight loss). Eligible patients were randomly assigned within each of the
      four strata to one of the two treatments (one or six weeks re-feeding) in blocks of size two,
      with equal allocation of treatments within each block. The randomization list was generated
      with a pseudo-random number generator, so that the resulting treatment sequence was
      reproducible and unpredictable.

      The treatment allocation order was arranged in numbered, sealed envelopes and kept in
      separate boxes for each strata. At patient assignment, the envelope next in order was drawn
      from the appropriate strata box.
    

Intervention name(s): Re-feeding duration
Intervention type(s): Behavioral
Intervention description(s): 1 or 6 weeks of re-feeding after VLED-induced weight loss
Other intervention name(s): Dietary advice
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Obesity; Weight loss; Diet; Very-low-energy diet; Predictive factors; Re-feeding