Among general reasons for the possible harmful effects of dietary supplements are: a) absorption in a short time, b) manufacturing quality and contamination, and c) enhancing both positive and negative effects at the same time. The incidence of liver injury from herbal and dietary supplements is about 16–20% of all supplement products causing injury, with the occurrence growing globally over the early 21st century. The most common liver injuries from weight loss and bodybuilding supplements involve hepatocellular damage with resulting jaundice, and the most common supplement ingredients attributed to these injuries are green tea catechins, anabolic steroids, and the herbal extract, aegeline. Weight loss supplements have also had adverse psychiatric effects.
The Natural Nutritional Foods Association estimated that in 2003 nutritional supplements amounted to a $19.8 billion market in the United States. By category, vitamins provided $6.6 billion in sales, herbs $4.2 billion, meal supplements $2.5 billion, sports nutrition products $2.0 billion, minerals $1.8 billion, and specialty and other products totaling $2.7 billion. The nutritional supplement industry provides a huge array of products for consumer needs.
And, once I have my burger or pizza or margarita or whatever, I go back to my normal healthy eating. And this works well for me. The funny thing is I usually don’t even enjoy the cheat days as much as I think I will because I find the foods too salty or too sweet or too greasy. I actually can’t wait to get back onto my normal, healthy foods as soon as possible.
If you do decide to diet, you still need to maintain good nutrition. You want to cut back on calories, not nutrients. And while you want to reduce fat, don't eliminate it entirely. Some studies suggest that older women who maintain a higher body-fat percentage are less likely to suffer from osteoporosis and other conditions associated with menopause. Fat cells also retain estrogen, which helps maintain the calcium in your bones. Younger women should be careful, too: a low body fat percentage can lead to infertility; below 17 percent may lead to missed periods, also known as amenorrhea.
To help you learn how to eat healthfully, start with the U.S. Department of Agriculture's (USDA) dietary guidelines system, which you can find at http://www.mypyramid.gov. The MyPyramid system, which looks somewhat like the familiar food pyramid of old, offers guidance based on individual needs and replaces "serving" recommendations with actual amounts of food. It also emphasizes the importance of balancing nutritious (and tasty!) food choices from all food groups every day with daily physical activity.
If you suspect that you have had a serious reaction from a dietary supplement, let your health care provider know. He or she may report your experience to the FDA. You may also submit a report to the FDA by calling 800-FDA-1088 or completing a form online. In addition, report your reaction to the dietary supplement company by using the contact information on the product label.