March is National Nutrition Month – Separate Science from fiction!
From the revised food guide pyramid, to the latest news about nutrient timing to enhance athletic performance, to the changing nutritional needs of growing kids and aging baby boomers, to the impact of calcium on weight loss, and the low-carb fad, nutrition is in the news! With so much information and misinformation, it is hard to separate fact from fad and science from fiction! Often the media reports research findings in “sound bites” that capture public attention, but leave out the details that make the whole story more complete and accurate. No wonder there is mass confusion leading to frustration and to food and supplement choices that are less than ideal – and that could be downright harmful!
One of the most important principles to remember about nutrition is that “one size does not fit all”. And, unless you want to “super size” yourself, avoid “super size” portions. When it comes to serving sizes to the number of servings per day, and to supplement needs, all that will vary depending upon age, gender, body composition, special health considerations, and level of physical activity. For example, toddlers need smaller portions than older children; muscular athletes need more calories than their less muscular and less active counterparts (greater muscle mass increases metabolism); older adults and pregnant women need more folic acid (400-800 mg). Teenage and post-menopausal women need more calcium—and half that amount in magnesium to enhance calcium absorption. 1300 mg of calcium is generally recommended for teenagers, and 1200-1500 mg for post-menopausal women, depending upon bone health. And while calcium, specifically from unsweetened yogurt, has been associated with weight loss, excessive amounts are associated with higher incidence of kidney stones and can interfere with the absorption of iron, zinc and potassium! The Upper Intake Level for safe consumption is 2500 mg/day (food and/or food and supplements combined). [Look for more on calcium, magnesium, Vitamin D and bone health in future issues.]
As for nutrient timing for pre and post exercise, protein/carb combos seem to work best. It is important to include these in your daily calorie count so that these calories enhance muscle recovery, glycogen replenishment, and performance rather than get stored as fat! Pre-exercise snacks needs will vary with intensity, duration and type of workout. Re-fueling after a workout is essential, preferably within 30 minutes of finishing to insure glycogen replenishment (glycogen is stored energy from carbs in the muscle and liver). Some examples of protein/carb combos would be whole grain bread and natural peanut butter; cottage cheese and fruit; nuts and apple; chicken or tuna or beans and rice.
What about the low-carb craze and all the confusion about the glycemic index? First of all, not all carbs are created equal. There is a big difference between a cup of broccoli and a can of soda! And the glycemic index of a meal differs from the glycemic index of any individual food in that meal. The combination of foods and beverages consumed makes up the glycemic index of the meal. And attention to the glycemic index will be different for individuals with diabetes than for those who are not diabetic. Type, intensity, and timing of exercise will also matter.
For accurate information about nutrition, please go to the American Dietetic Association website at www.eatright.org; for information more directly related to nutrition and physical activity, go to The American Council on Exercise website at www.acefitness.org.
The bottom line is to be active on most days of the week, eat plenty of fruits and vegetables, adequate lean protein, healthy fats (like olive oil, nuts, seeds – more on this in a future issue), and whole grains which are high in fiber. Drink plenty of water and avoid sodas and processed, refined foods.
And as for those claims that seem too good to be true – beware! It if sounds too good to be true, it probably is. And if you’re looking for a miracle – exercise has over 50 scientifically proven health benefits – so get moving! Enjoy a heart-healthy meal with family or friends and go out for a walk. It’s not only sensible – it’s fun!