The purpose of this study is to measure the effects of a Health-At-Every-Size (HAES) approach on global health status of premenopausal overweight women preoccupied about their weight and who have been unsuccessful in previous weight loss attempts.

Weight management is a critical issue in developed countries where the prevalence of obesity is increasing. Poor long-term success observed with current weight-control strategies stresses the relevance to explore new weight management approaches. One of these approaches, referred to as Health-At-Every-Size (HAES), is a new weight paradigm that focuses on a healthy lifestyle by promoting overall health benefits of behavioral changes related to dietary habits and physical activity and emphasizes self-acceptance and well-being, independently of body weight status. Studies on the effects of a HAES approach have shown significant improvements in metabolic and psychological variables.

To our knowledge, no study has yet reported the short and long-term impacts of a HAES approach on a cluster of variables (psychological, morphological, metabolic, and nutritional) in women. The aim of this study is to measure the effects of a HAES approach on global health status of premenopausal overweight women preoccupied about their weight and who have been unsuccessful in previous weight loss attempts. In this parallel controlled trial, women will be randomized to one of the 3 treatment conditions: HAES group, Social support group (SS), or Control group. Measurements will be taken in the short term as well as in the long term (up to 1 year post-intervention).

Inclusion criteria:

• Healthy premenopausal women from Quebec City metropolitan area
• Age: between 30 to 50 years old
• Stable body weight (+/- 2 kg) for at least 2 months before the beginning of the study
• Overweight or obesity: Body mass index [BMI] between 25 and 35 kg/m2
• Preoccupation about weight and eating: showing overconcern with shape and weight, exhibiting restriction over food choices for at least 2 years, and having been unsuccessful in previous attempts to lose weight (for at least the past 2 years)
• Current weight corresponding to maximum weight reached during adult lifetime

Exclusion criteria:

• Women currently dieting to lose weight
• Taking oral contraceptives or postmenopausal status
• Pregnant or lactating women
• Under treatment for coronary heart disease, diabetes, dyslipidemia, hypertension, depression or endocrine disorders (with the exception of stable thyroid disease)
• Women presenting metabolic or important psychological disorders (drug or alcohol abuse, bulimia, …)
• Women who had already take part to the Health-At-Every-Size (HAES) approach