Sara Wilson is a graduate student in nutrition communications at the Friedman School of Nutrition Science and Policy. She has a B.S. in nutrition from Syracuse University and is a registered dietitian. Prior to coming to Tufts, Sara worked as a clinical dietitian in an intensive care unit of Legacy Emanuel Hospital in Portland, Ore.
Q. We have been learning about BMI in health class, and I know it has something to do with how much you weigh. But I used the formula to calculate my BMI, and it says that I am considered "overweight." How is this possible? I work out and lift weights regularly and watch what I eat.
A. BMI, or body mass index, is a measure of the ratio of your weight to height. It can be calculated as weight (in kilograms) divided by height (in meters squared), or by looking on a chart. BMI is a rudimentary measure of weight status (whether underweight, normal, or overweight) and a simple way to assess your risk for weight-related health problems.
But BMI does not account for muscle mass. People with more muscle mass, such as athletes, trainers, or those who lift weights and exercise, may find that they weigh more since, pound for pound, muscle weighs more than fat. This can make your BMI higher, or put you in an "overweight" category, even if you're at a perfectly acceptable weight considering your fitness level. The best way to tell how much fat mass you have, and to better indicate your level of health, is to measure your body fat percent, either with calipers, a special scale, or bioelectrical impedance.
Q. I'm a total ice cream addict. Now that the weather is warmer, I'm finding it increasingly difficult to go a day without a trip to J.P. Licks. How can I keep ice cream in my diet for the summer without compromising my usually healthful eating habits?
A. Certainly, daily trips to J.P. Licks could take a toll on your diet. But you can fit ice cream into a healthful diet. If you can manage, a weekly, or bi-weekly, trip is probably the most you want to visit the ice cream shop, especially if you are getting the regular ice cream. Aim for a small or child's size portion; portion control can mean the difference between a once a month outing and weekly outings. If you are able to keep the amount to a minimum, you will likely be able to incorporate that ice cream into your weekly diet, given that you account for your J.P. Licks visit in your total daily calorie intake. Another option is to order the frozen yogurt, especially the non-fat or low-fat type. You will save on both calories and fat with this, and once in a while, will allow for added toppings such as sprinkles or Oreo bits.
Q. What is the difference between an "antioxidant" and a "vitamin"? Can a vitamin be an antioxidant?
A. An antioxidant is a compound that protects other compounds (or tissues or organs) from oxidation (the interaction of a tissue with the damaging effects of reactive oxygen). These reactive oxygen compounds, called free radicals, can cause cell damage that may lead to health problems such as cancer, heart disease, and arthritis. A vitamin is an organic compound that is necessary to life and body function.
Many vitamins act as antioxidants, although not all antioxidants are vitamins. Vitamins C and E, and beta carotene (which forms vitamin A), play a role in neutralizing these free radicals. Other antioxidant substances, such as phytochemicals produced by plants - and found in tomatoes, red, yellow and green vegetables, and soy, for example - offer some of the same protective effects as antioxidant vitamins. Fruits and vegetables are the best sources of vitamin C, beta carotene, and phytochemicals, while vitamin E can be found in oils, salad dressings, and nuts. If you don't get your "5 a Day" of fruits and vegetables, take a multivitamin. Even if it doesn't contain the phytochemicals found in fruits and veggies, it still provides you with vitamins A, C and E.
Q. What is the best to eat or drink the day after a night of drinking? Are there certain nutrients the body needs to replace?
A. Unfortunately, there is no magic food or drink that can restore you after a night of drinking. What is probably most important, and helpful, is to drink a glass of water before you go to bed, and plenty the next day. That hangover is caused in part by dehydration of the brain cells, and the accompanying rehydration - or swelling of the brain cells - after a night of drinking. Drinking fluids can help to correct the body's chemistry.
In addition, there are some important nutrients that may need to be replenished the next day. Because alcohol intake increases urine output, you may be at risk for losing certain minerals as you make those many trips to the restroom throughout the night. It is important to replace magnesium, potassium, calcium and zinc after a night of drinking; a bowl of fortified cereal with milk, a cup of yogurt or some browned potatoes can help do the trick - and perhaps get your new day off to a better start.
