Effectiveness of Gradual Versus Rapid Weight Loss

Comparative Effectiveness of a Gradual Weight Loss Program and a Rapid Weight Loss Program (Including a Low Energy Diet) on 1-year Weight Loss in Subjects With Obesity - A Randomized, Parallel-group, Superiority Trial. (The GoLow Study).

This randomized controlled trial aims to compare the 1-year effectiveness of an initial rapid weight loss (RWL) program and a gradual weight loss (GWL) program.

A total of at least 286 participants will be randomized to either a 16-week rapid weight loss (RWL) program; [an 8-week low-energy-diet (<1000 kcal/day) - followed by an 8-week gradual increase in energy intake (4 weeks <1300 kcal/day and 4 weeks <1500 kcal/day)], or a 16-week gradual weight loss (GWL) program (controls); [estimated total energy expenditure minus 800-1000 kcal/day]. Thereafter, all participants (both groups) will undergo a 36-week comprehensive weight maintenance program.

Inclusion Criteria:

• • Willing and able to give informed consent for participation in the study

  • Living in the eastern part of Norway, mainly Oslo, Buskerud, Vestfold and Akershus
  • Understanding Norwegian language written and spoken easily
  • BMI ≥30.0 kg/m2
  • Stable body weight (<5 kg self-reported weight change) during the last 3 months before inclusion

Exclusion Criteria:

• • Pregnancy and breast-feeding mothers

  • Suspected non-compliance with regards to visits and/or diet
  • Severe chronic disease (endocrine disease, heart disease, neurological disease, lung disease, disease in the gastrointestinal tract, kidney disease, rheumatism or cancer).