More gym-class time does not lower child obesity


Extra time in gym class does not appear to do anything to reduce child obesity. So, what can you do to help an overweight child? Or yourself, for that matter, if this is a concern for you?

This news from the Canadian Pediatric Society conference held in Victoria, British Columbia, at first glance may seem surprising. Exercise helps one lose weight, right? Well according to this analysis of studies of school activity interventions done on 10,000 children in BC comparing Body Mass Index (BMI) before and after the intervention, there was no change in BMI, even in the studies where the activity interventions lasted three years. The studies analysis did show improvements in health measures like blood pressure, bone density, aerobic fitness and range of motion, but none of the studies showed a drop in bodyweight. This follows on the heels of another study done on 900 teens in grades 10 to 12 in the Vancouver area studied by researchers at University of British Columbia and McGill University in Montreal, who found “… there appeared to be no link between body mass index (BMI) values and levels of physical activity”

Body Mass Index is a simple measure used to compare one’s height to one’s weight (Weight in kilograms divided by height in meters squared). A healthy BMI is considered to be between 18.5 and 25, overweight between 25 and 30, and obese, over 30. This measure is frequently used in studies, and is well understood by health professionals. I think the number can be very misleading, however. For example, a very muscular male can weigh a great deal (muscle weighs more than fat), and still be very lean, but may have a BMI over 30. I find waist/hip ratio or even simply a waist measurement to be far more useful for before and after measurements.

The study results are a blow to those who are advocating for daily quality physical education in the schools, as it may be harder to convince officials to take children away from reading, writing and arithmetic if physical activity does nothing to stem the obesity tide. I hope those officials see the big picture, however. I think the goals of a physical education program should be to help children learn to love moving their bodies, so that they continue to do so when they are adults.  And the health benefits of reduced blood pressure, increased bone density, improved aerobic capacity, improved range of motion about joints, not to mention improved mental concentration are worth the time spent on daily physical education. There is no question about the increased health benefits gained from better physical fitness.

So, if your child is overweight (and if you or someone you know is overweight), what are some strategies that may work to lower body fat?

  1. Control blood sugar and insulin levels, in order to reduce fat storage and encourage fat burning by:
    1. Reducing or eliminating sugar as much as possible – soda pop, juice, fruit drinks, candies, cookies, cake, puddings, sweetened yogurts etc.
      1. replacing with fresh fruit (not dried or canned) if something sweet is needed
      2. Encouraging water and raw milk (if tolerated) from grass-fed cows as the beverages of choice
      3. de-emphasizing desserts
      4. Using an activity as a treat rather than sweets
    2. Eliminating junk food – chips, cheesies, crackers, boxed breakfast cereals, pop tarts, boxed waffles, pre-mixed sauces, dressings etc. – anything that comes from a factory.
    3. Limiting the starches like white bread, pasta, white rice etc.
    4. Reading labels and avoiding artificial sweeteners – the liver stores toxins in fat tissue.  Use stevia to sweeten if needed.
    5. Choosing REAL food snacks, like a generous piece of raw cheese with some carrot sticks or an apple, a chicken leg, a hard-boiled egg, veggie sticks with a home-made full-fat yogurt dip or unsweetened nut butters.
      1. Quality fats are nourishing, not particularly fattening, and they decrease hunger.  If not sensitive, give even obese children some full-fat dairy like whole milk, raw cheese, butter, ghee etc. Girls do especially well when quality fats are included in their diet, according to this article on children's nutrition by Dr. Tom Cowan. Quality fats are needed for neurological, immune and hormone system development.
      2. Protein foods like meat, poultry and fish help children grow, decrease hunger, and are especially important for boys according to this article on children's nutrition by Dr. Tom Cowan.
      3. Vegetables are often not liked by children, so mixing with real cheese (broccoli/cauliflower and cheese sauce) or cream (creamed spinach) may help. Broccoli and cheese sauce is a MUCH better choice than macaroni and cheese sauce.
    6. Reading labels on medications/multi-vitamins – they often contain sugar or sweeteners
  2. Ensure bedrooms are completely dark – night-time light messes withhormones, and hormones determine bodyweight.
  3. Reduce screen time (TV and computers), and get them out of the bedroom. Not only does TV watching often go hand in hand with munching, but also advertisers market directly to kids, changing their food preferences for poorer quality food. I don't think I have ever seen a TV commercial for broccoli!
  4. Do physical activity as a family (bike riding, walks, hiking etc.) to encourage life-long activity, and also to stop the lounging on the sofa watching TV syndrome. Teens that have reached their adult height can incorporate weight training into their life, which will increase insulin sensitivity.
  5. Reduce or eliminate food products and skin products that have a long list of chemical ingredients. The liver stores toxins as fats, so ahigh toxic load may prevent the body from losing fat.
  6. Drinking a big glass of water before meals may help by filling the stomach, reducing hunger.
  7. Give your child a quality probiotic to improve the gut bacteria. There are many studies now indicating that the wrong bacteria in the gut can be a risk factor for obesity. There are probiotics made for kids available.

If you want to learn how and what to feed your children from infancy through the teenage years, I cannot recommend highly enough this article called "Feeding our Children". Children fed this way will be healthy, vibrant, and will learn and appreciate how to nourish themselves as adults.

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Related tips
Obesity – a behavioural or a metabolic problem?
How we become over-fat
Insulin, our storage hormone
Is going to bed too late making you fat?
Television watching is a health risk
Want fat loss? Aerobic exercise alone is not the answer
Bacteria, the soil, the gut and detoxification

Canadian Association for Health, Physical Education, Recreation and Dance Phys-ed won’t cut child obesity, study says Pamela Fayerman, Vancouver Sun, Published: Thursday, June 26, 2008.

McGill University Physical activity, healthy eating and BMI not linked in older teens: Results from under-researched 15- to 18-year-old group challenge established assumptions Apr. 30, 2008.

Cowan, Thomas Dr. Feeding our Children Four Fold Healing. Holistic Family Medicine.

Formby and Wiley; Lights Out!
Sugar, Sleep and Survival
Pocket Books, New York, NY, 2000.

Taubes, Gary

Good Calories, Bad Calories, Challenging the Conventional Wisdom on Diet, Weight
Control, and Disease
Alfred A. Knopf, New York, 2007.

Price, Weston A.

Nutrition and Physical Degeneration
Price-Pottenger Foundation, La Mesa, CA,

Lumeng J. et al.
TelevisionExposure and Overweight Risk in Preschoolers Arch Pediatr Adolesc Med. 2006;160:417-422.

Taheri S.The link between short sleep duration and obesity: we should recommend more sleep to prevent obesity Archives of Disease in Childhood 2006; 91:881-884;

Tremblay A, et al.
Impact of exercise intensity on body fatness and skeletal muscle metabolism

Metabolism 1994 July;43(7):814-8.

Yoshioka M. et al.

Impact of high-intensity exercise on energy expenditure, lipid oxidation and
body fatness
Int. Journal of Obesity Related Metabolic Disorders 2001

Geliebter A. et al.

Effects of strength or aerobic training on body composition, resting metabolic
rate, and peak oxygen consumption in obese dieting subjects
American Journal of Clinical Nutrition  1997, Sept. 66(3):557-63.

Copyright 2008 Vreni Gurd

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1 Comment

  1. Nick said,

    May 10, 2009 @ 8:43 pm

    BMI is a terrible measure to use for this study, even like you said it is a simple measure. BMI only calculates the height and weight and takes nothing else into account, I personally can’t stand using BMI because it is too nonspecific. If you want more accuracy you should have used body fat % instead, so at least it would take into account more factors. The study even mentioned their being an increase in bone density, well that adds more weight to a person, also if the person is exercising they are building muscle, which weighs more than fat, so that could also add a little bit of weight. Which in turn makes your BMI worse and appear to being closer to being overweight or if you already are overweight then even more overweight. If you would have calculated body fat % instead of BMI you probably would have seen more improved numbers in the area of body weight based off of having lower body fat which is what you are wanting to go for anyway.

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