"Improving Diet, Exercise And Lifestyle (IDEAL) for Women" Study
Condition: Overweight; Obesity
MeSH terms: Overweight
Study type: Interventional

Summary: 
      Diets all share the same principle: eat less energy than you need. This results in weight
      loss. However, the weight loss is usually a combination of a loss of body fat and muscle
      mass. Additionally, one's bones may begin to weaken, albeit very slowly, while on a diet,
      which could have serious long-term consequences. Thus, the investigators believe that the
      goal of any weight loss strategy should be to lose body fat and spare muscle. The
      investigators reasoning is two-fold. 1) Fat is not only stored under the skin, but also in
      and around the internal organs. When this occurs, the organ itself may not function properly.
      Losing fat mass is a very good thing from a health standpoint, since fat is not just a
      storage site for extra energy. Scientists have now shown that 'extra' body fat itself can
      actually secrete substances and when these substances get into your blood, they cause many
      problems and may even contribute to the development of diabetes. 2) Sparing muscle as an
      individual loses weight is very important. Muscle is a very 'metabolically active' tissue and
      is, by analogy, like the body's furnace. Muscle burns fuel from the food individuals eat and
      also from stored fuels, like fat. Hence, it's easy to see why you don't want to lose muscle
      because you'd be losing one of your body's best fat burners. More importantly, muscle is also
      a big storage site and furnace for blood sugar. In people with diabetes (elevated blood
      sugar), a big part of the problem is with their muscles - they simply do not take up and
      store or burn enough sugar. For these reasons, your goal should be to lose fat and preserve
      muscle while dieting.

      There are many different diets to choose from (e.g. high protein, low carbohydrate, high fat,
      high fiber, etc.). A diet that has been shown to be quite successful, however, is one that is
      higher in protein (but not excessive). Thus, in this study, the investigators are proposing
      to test whether a higher protein (with dairy) and calcium diet promotes body fat loss and
      muscle mass retention. The investigators believe that a diet higher in protein (with an
      emphasis on dairy), but still within accepted healthy ranges, with higher dietary calcium may
      result in greater loss of body fat and retention of muscle than a diet with a conventional
      amount of protein and adequate calcium or a conventional amount of protein with little
      calcium (i.e. low dairy). Based on previous research, the investigators think that people
      with low calcium intakes to begin with would stand to benefit the most. There is also a good
      reason to think that the high protein/high calcium diet may result in greater reductions in
      blood cholesterol and blood sugar, both of which would reduce a person's risk for heart
      disease and diabetes.

      The investigators will test this diet in premenopausal women who are overweight or obese. The
      investigators believe that this group is a good one to target for several reasons. First,
      women of this age who are overweight or obese are, if they continue to carry this excess
      weight, are at serious risk for developing chronic diseases such as heart disease, diabetes,
      and possibly cancer at an early age. Second, these women will often begin to gradually
      consume less dairy because many perceive dairy foods as fattening. Thus, if the investigators
      proposals are correct the investigators will hopefully be able to equip health professionals
      with a tried and tested, palatable, dietary strategy in a population segment who, because of
      their age, would benefit greatly were their disease risk to be reduced.
    

Detailed description: 
      Overweight to obese female subjects, who are habitually low dairy consumers and between the
      ages of 19-45 years will be recruited from the McMaster University student and staff
      population and from the surrounding Hamilton area. At study entry, all subjects will be asked
      to complete a standard screening questionnaire to document their medical history, current
      medication use, physical activity level, smoking habits, and alcohol consumption. Subjects
      will also complete a calcium food frequency questionnaire. Before randomization and study
      commencement, baseline measures will be done. These include: anthropometrics, fasting blood
      samples, fasting urine sample, resting energy expenditure measures (REE), muscle and adipose
      biopsies, cardiovascular measures (blood pressure, heart rate, blood vessel stiffness and
      arterial elasticity) body composition (dual-energy x-ray absorptiometry [DXA]), and a 7-day
      baseline food record analysis. Also, subjects' strength and fitness will be assessed (1
      repetition maximum (RM) and submaximal Astrand Test evaluations). During the study, fasting
      blood samples will also be taken at weeks 4, 8, 12 and 16, DXA will also be done at weeks 8
      and 16, validated Body Image questionnaires will be filled out again t weeks 8 and 16, and
      body weight will be recorded every week. All other measures will be repeated after 16 weeks
      (1RM, Astrand Test, biopsies, cardiovascular measures, REE). Magnetic Resonance Imaging (MRI)
      will be carried out on a smaller portion of subjects on a voluntary basis at weeks 0 and 16.
      Apon completion of the baseline testing, subjects will be randomly assigned to one of the
      three intervention groups.

      Part of the intervention will be in the form of 2 daily chocolate drinks (a post-exercise
      drink plus one extra drink per day). Drink composition will differ depending on which group
      subjects are randomized to. Drinks will be made to look and taste similar. In terms of the
      daily diets, the DairyPro (middle/second) group will employ the same macronutrient
      distribution as the Control (first) group but half the protein will be derived from dairy
      sources, with subjects being asked to consume, on top of their supplemental chocolate drink,
      2 yogurts (100 g each). In the control group, protein will be derived from sources other than
      dairy. In the HiDairyPro (third) group, dietary protein will be manipulated so as to comprise
      twice as much dietary energy versus the other two groups (i.e., 30% of energy intake versus
      15%). Protein (half of their daily requirement) will be derived from dairy protein by asking
      subjects to consume, on top of their supplemental chocolate drink, 1 serving (250 ml) of 1%
      regular milk, 4 yogurts (100 g each) and 2 pieces of cheese (21 g each).

      Overview of supplemental drink composition and diet composition by group:

        1. Control (Con) - a group consuming twice daily drinks containing no dairy protein or
           calcium. Daily protein (15% total kcals) should be from non-dairy sources (i.e. meat,
           egg, fish, chicken, lentils, beans, wheat gluten).

        2. Dairy Protein Group (DairyPro) - a group consuming twice daily drinks containing 1%
           chocolate milk and at least half of their daily protein (15% total kcals) intake from
           dairy sources.

        3. High Dairy Protein Group (HiDairyPro) - a group consuming twice daily drinks containing
           1% artificially sweetened chocolate milk along with a diet formulated to contain 30% (as
           opposed to only 15% in the Con and DairyPro groups) of their dietary energy from protein
           with at least half of that coming from dairy protein.

      Subjects will meet with a study dietitian/nutritionist at the beginning and biweekly
      throughout the 16 weeks, and be provided with individual dietary counseling to reduce daily
      calories by 500 kcal/d. Subjects will be provided with template diet records, nutrition
      information sheets and macronutrient specific exchange lists to help with dietary compliance
      and to promote healthy food choices. The weight-reducing diets will have macronutrient and
      micronutrient profiles that are in accordance with the dietary regulations set forth by
      Canada's Food Guide and the dietary reference intakes (DRIs). The macronutrient profile of
      the 2 moderate protein groups (control and DairyPro) will be 15:30:55 (PRO:Fat:CHO), whereas
      the subjects in the High dairy protein group (HiDairyPro) will consume a profile of 30:30:40
      (15% substitution of carbohydrate for protein). Subjects will consume all other food (aside
      from their designated drinks) in any manner they choose in accordance with the macronutrient
      profile of their respective randomization allocations. Adherence to the prescribed diet will
      be via collection of assigned biweekly food records, frequent contact with subjects, and
      regular dietary counseling sessions.

      In addition, all subjects will be given a custom exercise prescription consisting of
      supervised resistance exercise and aerobic exercise. Intensity and duration of all exercise
      sessions will be monitored and energy expenditure quantified using portable, validated units
      that integrate accelerometry, heat flux and skin temperature. Exercise will take place in a
      supervised setting at McMaster University. Subjects will perform exercise 7d/wk and will
      exercise supervised 5d/wk (Mon - Fri). Resistance training sessions will take place 2x/week.
      During these sessions, subjects will engage in a circuit weightlifting routine using guided
      motion machines.
    

Intervention name(s): Exercise - Aerobic and Resistance; Dietary - Caloric Restriction
Intervention type(s): Behavioral; Behavioral
Intervention description(s): Subjects will perform exercise (aerobic and resistance) 7d/wk and will exercise supervised 5d/wk. Exercise will be carried out to expend 250 kcals/day. Supervised resistance training sessions will take place 2 days/wk and aerobic exercise will take place every day. During the resistance exercise sessions, subjects will engage in a circuit weightlifting routine using guided motion machines. During the aerobic sessions, subjects may choose whatever exercise modality they like (e.g. walking on track or treadmill, biking, elliptical, etc.). Subjects will wear devices that measure energy expenditure to get a better idea of the intensity and duration needed to expend 250 kcals with their exercise machine/modality of choice.; Subjects will be counselled on their respective hypocaloric diets during the 16 wk period. Adherence to the prescribed diet will be assessed via collection of assigned food records (biweekly), frequent contact with subjects, and regular dietary counseling sessions. The daily dietary energy deficit will be 500 kcal per day based on the subjects' estimated daily caloric requirements (based on height, weight, age, sex), multiplied by a sedentary activity factor.
Additionally, subjects will consume 2 drinks per day that will differ depending on their randomization allocation. Subjects in the Dairy Protein and High Dairy Protein group will be provided with dairy products (e.g. milk, cheese, yogurt) to consume on a weekly basis to help facilitate their prescribed dairy and dietary protein intake.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Dairy Products; Dietary Protein; Body Composition; Fat mass loss; Lean mass gain; Pre-menopausal Women