Weekly Column_120 / August 16, 2012

Diet Detective Goes Beyond the Headlines: Low GI Diets, Exercising Away the Common Cold, Teach Your Children Well and Carrot Tanning

By Charles Platkin, PhD

Low-Carb Diets Rule

A study from researchers at the University of Copenhagen published in the New England Journal of Medicine found that if you want to lose weight and keep it off, you need to cut out refined starches — that is, all the white stuff (breads, rice, cakes, etc.) ­ and stick to a diet that is high in proteins, including lean meats and beans. The researchers looked at a total of 772 families, comprising 938 adult family members and 827 children, making this one of the world’s largest controlled studies. The overweight adults followed an 800–calorie–per–day diet for the first eight weeks, losing an average of 24 pounds. They were then randomly assigned to one of five different low–fat diets, which they followed for six months to test which was most effective at preventing weight regain.

What worked best for keeping the weight off was a high–protein, low glycemic index (GI) diet. (According to the study definition, GI is “a measure of the ability of carbohydrates to increase blood glucose levels when absorbed in the body. Food with a low glycemic index causes blood glucose levels to increase more slowly and to lower levels compared to high–carbohydrate foods with a high glycemic index.”) Based on this study and the new Gary Taubes book, Why We Get Fat, it seems that carbs are the enemy again. (You can read my interview with Gary Taubes here.)

The Treadmill vs. The Common Cold

Research reported in the British Journal of Sports Medicine found that people who are physically fit and active have fewer and milder colds. The researchers tracked 1,000 adults during the fall and winter and found that when they had a cold “symptoms fell by 41 percent among those who felt the fittest and by 31 percent among those who were the most active.” The researchers theorized that working out increases the circulation of immune system cells and helps to fend off viruses and bacteria.

What about once you already have a cold? Experts from the American College of Sports Medicine (ACSM) recommend caution for people who are considering an intense workout while they’re sick. “Prolonged, intense exercise…can weaken the immune system and allow viruses to gain a foothold and spread. People who are already sick should approach exercise cautiously during their illness.” ACSM experts offer the following recommendations:

  • Do exercise moderately if your cold symptoms are confined to your head. If you’re dealing with a runny nose or sore throat, moderate exercise is permissible. Intense exercise can be resumed a few days after symptoms subside.
  • Don’t “sweat out” your illness. This is a potentially dangerous myth, and there is no proof to support that exercise during an illness helps cure it.
  • Do stay in bed if your illness has spread beyond your head. Respiratory infections, fever, swollen glands and extreme aches and pains all indicate that you should rest up, not work out.
  • Don’t jump back in too soon. If you’re recovering from a more serious bout of cold or flu, gradually ease back into exercise after at least two weeks of rest.
  • In general, if your symptoms are from the neck up, go ahead and take a walk, but if you have a fever or general aches and pains, rest up.

Did You Ruin Your Child’s Eating Habits?

Researchers from the Johns Hopkins Bloomberg School of Public Health analyzed studies published since 1980 that looked at children’s and parents’ dietary intake. What they found is that parents don’t have as much influence as previously thought. Researchers believe that children’s eating habits are influenced by many factors, including schools, local food environment, government guidelines that regulate school meals “and the broader food environment that is influenced by food production, distribution and advertising.” This doesn’t mean parents are off the hook — just that they’re not completely responsible. Parents should still set a good example and eat healthfully (fruits, vegetables, whole grains, low–carb and low–fat) in front of their kids — it matters.

Eat Your Way to A Good Tan

Next time you think you need to sit in the sun and get a tan to look attractive — think again. A study led by Dr. Ian Stephen at The University of Nottingham showed that eating a diet rich in fruits and vegetables gives you a healthier glow. Dr. Stephen and colleagues found that people who eat more fruits and vegetables have a more golden skin tone because of substances called carotenoids — “antioxidants that help soak up damaging compounds produced by the stresses and strains of everyday living.”

These carotenoids are responsible for the red coloring in fruits and vegetables such as carrots and tomatoes, and are important for improving immune and reproductive system functions. The study found that, when given a choice, people preferred those with a skin tone caused by carotenoids to those who were suntanned. The reason? Carotenoids signal health in bird and fish species and are associated with improved immune defense, photoprotection and reproductive health in humans. Stephen speculates that carotenoid skin coloration provides a “perceived health” and that this is “a valid cue to human health, which is perceptible in a way that is relevant to mate choice, as it is in bird and fish species.”






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Diet Detective's Guide to Casual Dining Restaurants 2011 Part 1, Outback, Red Lobster and Applebee's
I’ve included only calories, not all the other nutritional information, but that doesn't mean carbohydrates, fiber and sodium...