Energy Intake, Exercise and Constitutional Leanness

Body composition (using X-ray absorptiometry), muscle strength (biodex), daily energy intake (dietary record), food preferences (Leeds Food Preference Questionnaire) and physical activity level (GT3X accelerometers) will be assessed among women with constitutional leanness normal weight women and women with anorexia nervosa. The CT and NW groups will then be asked to randomly realized three experimental session: i) a rest session with an fixed lunch meal; a rest session with an ad libitum meal ; iii) an exercise session with an ad libitum meal. Their ad libitum energy intake will be assessed during the two last sessions. Appetite feelings will be assessed at regular intervals and their food reward in response to the lunch will also be assessed.

Inclusion criteria

• Common criteria to the three groups
• Women
• Aged 18 to 35 years old

-- Signed consent form

• being registered in the national social security system
• no contraindication to physical activity

Criteria specific to constitutionally lean women

• BMI ≤ 17.5 kg/m2
• Weight stable for the last three months
• No dietary disorders
• no sign of denutrition
• absence of amenorrhea

Criteria specific to women with anorexia nervosa

• BMI ≤ 17.5 kg/m2
• Pure restrictive Anorxia nevrosa: no binge eating or vomiting episodes for the last thress months.
• DSM V (2013) crietria Criteria specific to normal weight women
• 20 kg/m2 ≤ BMI ≤ 25 kg/m2
• Weight stable for the last three months
• No dietary disorders
• no sign of denutrition
• absence of amenorrhea

Exclusion criteria

• Pregnancy
• Intensive physical activity level (aboce 3 sessions per week)
• Impaired level of IGF-1, estradiol, T3free, cortisol and leptin (for normal weight and constitutionally lean women)
• Previous surgical interventions that is considered as non-compatible with the study.
• Diabetes
• Medication that could interfer with the study.
• cardiovascular disease or risks
• Surgery within the last 3 months