Two studies were conducted to compare characteristics of consumers and non-consumers of vitamin and/or dietary supplements (study 1) and to assess the effect of a multivitamin and mineral supplementation during a weight-reducing programme (study 2). Body weight and composition, energy expenditure, and Three-Factor Eating Questionnaire scores were compared between consumers and non-consumers of micronutrients and/or dietary supplements in the Québec Family Study (study 1). In study 2, these variables and appetite ratings (visual analogue scales) were measured in forty-five obese non-consumers of supplements randomly assigned to a double-blind 15-week energy restriction (22930 kJ/d) combined with a placebo or with a multivitamin and mineral supplement. Compared with non-consumers, male consumers of vitamin and/or dietary supplements had a lower body weight (P, 0·01), fat mass (P,0·05), BMI (P,0·05), and a tendency for greater resting energy expenditure (P¼ 0·06). In women, the same differences were observed but not to a statistically significant extent. In addition, female supplements consumers had lower disinhibition and hunger scores (P,0·05). In study 2, body weight was significantly decreased after the weight-loss intervention (P,0·001) with no difference between treatment groups. However, fasting and postprandial appetite ratings were significantly reduced in multivitamin and mineralsupplemented women (P,0·05). Usual vitamin and/or dietary supplements consumption and multivitamin and mineral supplementation during a weight-reducing programme seems to have an appetite-related effect in women. However, lower body weight and fat were more detectable in male than in female vitamin and/or dietary supplements consumers.Obesity: Weight loss: Micronutrients: Energy expenditure: Appetite Above the fundamental roles of physical activity and a macronutrient-balanced diet in the maintenance of a healthy body weight, evidence is pointing toward other dietary factors, admittedly of a lower impact range, that could affect energy balance on a long-term basis and therefore represent an avenue worth considering under obesity treatment circumstances. Ca is a good example of this, as low consumption of this micronutrient has been shown to be inversely associated with body weight and adiposity in many studies (1 -3) . More recently, it was observed in a large cohort of 15 655 individuals that overweight or obese men and women who had a high consumption of multivitamins, vitamin B 6 , vitamin B 12 or Cr had gained less weight than those who had not consumed these supplements over 8-12 years (4) .How vitamins and minerals could be implicated in the regulation of body energy stores is not known. For instance, one could propose that they influence the control of food intake through their roles in neurotransmitter synthesis and regulation in the central nervous system. Vitamins C and B 6 are good examples of this, since they are respectively involved in the hydroxylation and decarboxylation of tryptophan for the synthesis of serotoni...
