Evaluation of the Association Between the Menstrual Cycle and Weight Loss in Healthy, Overweight Premenopausal Women
Condition: Obesity
MeSH terms: Overweight; Weight Loss
Study type: Interventional

Summary: 
      Achievement and maintenance of weight loss in obese individuals has proven difficult. Many
      hypotheses have suggested potential biological mechanisms to explain why weight loss attempts
      often fail, and the surrounding obesogenic environment also seems an obvious candidate. Among
      the biological factors proposed is gender, and weight loss trials have frequently shown that
      females are less successful than males at losing weight and at maintaining weight loss.

      Women's weight is influenced by the menstrual cycle, in which changes in hormonal levels and
      interactions work to modulate fertility. These hormones control the menstrual cycle and
      coordinate the required changes in energy intake, expenditure, and storage, whilst preparing
      the body for pregnancy every month. As reproduction is a primary biological function, these
      hormones may be such strong mediators of eating behavior that they influence the outcome of a
      weight loss attempt. The menstrual cycle should therefore be taken into consideration as a
      factor in the physiology of energy balance in premenopausal women.

      The cycle can be divided into three phases: menstruation or early follicular phase (days
      1-5), late follicular phase that lasts until ovulation (~days 6-14, and the luteal phase
      (days 15-28).

      Studies have shown that in the luteal phase of the menstrual cycle, women's energy intake and
      energy expenditure are increased and women experience more frequent cravings for foods,
      particularly those high in carbohydrate and fat, than during the follicular phase. A trend
      towards reduced carbohydrate utilization and increased fat oxidation in the luteal phase has
      also been reported, together with prolonged time to exhaustion when exercising at submaximal
      intensities. This suggests that the potential of the underlying physiology related to each
      phase of the menstrual cycle may be worth considering as an element in strategies to optimize
      weight loss.

      In 2010 the investigators carried out a 90-day randomized, controlled pilot study in order to
      gain feedback on and assess acceptance of the meal and exercise plans being used and to
      observe if less control visits than planed in the main study were sufficient to achieve good
      compliance. Twenty eight were sreened and 24 were included. Subjects were randomized to
      either program A (given meal and exercise plans in relation to phases of their menstrual
      cycles) or Program B (a reduced calorie diet, calorie-matched to program A). The pilot study
      showed that Group A (The Menstralean group) tended to have a greater average weight loss at
      60 days (-5.29 vs -3.57 kg, p = 0.06) and 90 days (-4.22 vs -2.75 kgs, p = 0.2) compared to
      the control groups. There was a dropout rate of 27%. This was primarily due to an inadequate
      number of control visits and contact with the subjects. Thus the Menstralean program seems to
      have the potential to enhance weight loss in overweight and obese women. However, the main
      study has to be carried out with more subjects in each group in a longer duration and with
      more support and contact with the subjects.

      The aim of the present trial is to examine the impact of the menstrual cycle on weight loss
      attempts in healthy overweight (BMI > 27 kg/m2) premenopausal women (18-40 years) randomized
      to two different weight management programs for a period of 6 months.
    


Intervention name(s): Evaluation of the Association between the Menstrual Cycle and Weight Loss in Healthy, Overweight Premenopausal Women
Intervention type(s): Other
Intervention description(s): 2-arm parallel 6 month study with the obejective to examine the impact of the menstrual cycle on weight loss attempts in healthy overweight premenopausal women randomized to two different weight management programs. The women may not use hormonal contraceptive agents other than an IUD.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Keywords: Obesity; Weight reduction; premenopausal Women; Menstrual cycle; quality of life; food cravings