Q: If weight control is so important for lower risk of heart disease and cancer, why do I see high-calorie nuts included in so many health-oriented diets?
A: Nuts do contain many nutrients and health-protective compounds, but they are concentrated in calories, so don't sit down with a big bowl and engage in mindless eating in front of the TV. The key is to use them to replace another food (not just adding them to what you eat already) and choose smart portions of nuts, usually 1 ounce per day, about 1/4 cup. Studies with a variety of different nuts show that when people substitute nuts for foods such as fatty meat and deep-fried foods that are high in saturated or trans fats, blood cholesterol usually declines. Nuts contain mostly unsaturated fat that does not raise blood cholesterol, and they provide dietary fiber and small amounts of phytosterols that help control blood cholesterol. Brazil nuts are outstanding sources of the antioxidant mineral selenium. Almonds, hazelnuts, peanuts and Brazil nuts supply vitamin E, another antioxidant. Walnuts contain a broad range of potentially protective compounds, including ellagitannins, polyphenols (such as flavonoids and phenolic acids) and gamma-tocopherol. Finally, several large population studies link regular nut consumption with lower weight and less tendency to gain weight. So, if you monitor portion size there's no reason to let weight worries keep you from nuts' many protective nutrients.
Q: I've seen advertisements for home exercise programs that include something called plyometrics. It's supposed to be extra-effective for weight loss, but I'm wondering if it's safe for someone rather out-of-shape.
A: Plyometrics is a popular form of exercise today, included in a wide range of programs from boot camps at your local fitness center to sports conditioning classes. Plyometrics exercises come in many different forms, all of which focus on quick, explosive moves that aim for strength, power and speed all at once. Intensity is high, so while Plyometrics burns many calories and can be great for advancing cardiovascular fitness, the pace and form could be unsafe for someone who's out of shape. One common Plyometrics movement involves jump squats: you jump as high as you can, and then coming down, bend your knees to go directly into a squat, touch the ground and repeat a few times. For people at a high weight, this can result in a very large force coming down, and if the landing movement is not quite right, can lead to injury. Other Plyometric movements feature side-to-side jumps, which again can be great, but if you are out of shape or carrying a lot of excess weight, stepping down wrong in that side-to-side movement can lead to significant ankle or knee injuries. For unsupervised at-home exercise, it's extra important that you not attempt moves that could lead to injury if done incorrectly, or at an intensity that may be unsafe for you. Plyometrics is a vigorous enough program that if you are unfit or significantly overweight, you should check with your doctor first to make sure it's safe, and start with instruction from a certified fitness professional to learn proper technique. Proper footwear and a resilient surface are also important. For home exercise as you begin your fitness journey, choose challenging but less extreme programs, enjoy a relaxing and invigorating walk or simply turn on some music and dance.
The American Institute for Cancer Research (AICR) is the cancer charity that fosters research on the relationship of nutrition, physical activity and weight management to cancer risk, interprets the scientific literature and educates the public about the results. It has contributed more than $95 million for innovative research conducted at universities, hospitals and research centers across the country. AICR has published two landmark reports that interpret the accumulated research in the field, and is committed to a process of continuous review. AICR also provides a wide range of educational programs to help millions of Americans learn to make dietary changes for lower cancer risk. Its award-winning New American Plate program is presented in brochures, seminars and on its website, www.aicr.org. AICR is a member of the World Cancer Research Fund International.