Check the science. Make sure any claim about a dietary supplement is based on scientific proof. The company making the dietary supplement should be able to send you information on the safety and/or effectiveness of the ingredients in a product, which you can then discuss with your doctor. Remember, if something sounds too good to be true, it probably is.
Substances which the FDA regulates as food are subdivided into various categories, including foods, food additives, added substances (man-made substances which are not intentionally introduced into food, but nevertheless end up in it), and dietary supplements. The specific standards which the FDA exercises differ from one category to the next. Furthermore, the FDA has been granted a variety of means by which it can address violations of the standards for a given category of substances.

Look for supplements certified by the United States Pharmacopeia (USP), NSF International, or the United Natural Products Alliance, as it indicates a higher standard of quality assessment. (The USP's screening process, for instance, ensures that a product will break down properly and effectively release its ingredients into the body.) These organizations have a certification seal that is typically shown on the product packaging.
"Studies show that omega-3 fatty acids are cardio-protective and the basis for the AHA recommendation to consume fatty fish twice weekly," she says. "But the studies do not show that popping a supplement can have the same benefit in healthy individuals." She adds, "There is also a misperception that fish oils can lower cholesterol, but this is not true."
Maintaining a healthy weight is important piece of the puzzle to achieve good health. A healthy weight can be determined using the body mass index charts (see web source below). If you find you are overweight or obese, weight loss may be beneficial for you. Before you begin any weight loss efforts, consult with your medical provider and/or consult a registered dietitian to create a weight loss plan. If you are underweight, consult a medical provider to assess your weight status.
In the United States, it is against federal regulations for supplement manufacturers to claim that these products prevent or treat any disease. Companies are allowed to use what is referred to as "Structure/Function" wording if there is substantiation of scientific evidence for a supplement providing a potential health effect.[8] An example would be "_____ helps maintain healthy joints", but the label must bear a disclaimer that the Food and Drug Administration (FDA) "has not evaluated the claim and that the dietary supplement product is not intended to "diagnose, treat, cure or prevent any disease," because only a drug can legally make such a claim.[8] The FDA enforces these regulations, and also prohibits the sale of supplements and supplement ingredients that are dangerous, or supplements not made according to standardized good manufacturing practices (GMPs).
Calorie density. Junk foods are designed to convince your brain that it is getting nutrition, but to not fill you up. Receptors in your mouth and stomach tell your brain about the mixture of proteins, fats, and carbohydrates in a particular food, and how filling that food is for your body. Junk food provides just enough calories that your brain says, “Yes, this will give you some energy” but not so many calories that you think “That’s enough, I’m full.” The result is that you crave the food to begin with, but it takes quite some time to feel full from it.
Do you wonder if you need a dietary supplement? Maybe you do, but usually not. Ask yourself why you think you might want to take a dietary supplement. Are you concerned about getting enough nutrients? Is a friend, a neighbor, or someone on a commercial suggesting you take one? Some ads for dietary supplements in magazines, online, or on TV seem to promise that these supplements will make you feel better, keep you from getting sick, or even help you live longer. Often, there is little, if any, good scientific research supporting these claims. Supplements may cost a lot, could be harmful, or simply might not be helpful. Talk to your doctor or a registered dietitian for advice.
Create an eating style that can improve your health now and in the future by making small changes over time. Consider changes that reflect your personal preferences, culture and traditions. Think of each change as a “win” as you build positive habits and find solutions that reflect your healthy eating style. Each change is a MyWin that can help you build your healthy eating style. Use the tips and links below to find little victories that work for you.
After menopause. Lower levels of estrogen  after menopause raise your risk for chronic diseases such as heart disease, stroke, and diabetes, and osteoporosis, a condition that causes your bones to become weak and break easily. What you eat also affects these chronic diseases. Talk to your doctor about healthy eating plans and whether you need more calcium and vitamin D to protect your bones. Read more about how very low estrogen levels affect your health in our Menopause section. Most women also need fewer calories as they age, because of less muscle and less physical activity. Find out how many calories you need based on your level of activity.
Dietary supplements are complex products. The FDA has established good manufacturing practices (GMPs) for dietary supplements to help ensure their identity, purity, strength, and composition. These GMPs are designed to prevent the inclusion of the wrong ingredient, the addition of too much or too little of an ingredient, the possibility of contamination, and the improper packaging and labeling of a product. The FDA periodically inspects facilities that manufacture dietary supplements.