I've often heard that the amount of time spent watching TV is linked to obesity in children. Has anyone examined this relationship in adults?
ANSWER - A study recently reported in the American Journal of Public Health addressed that question, using a group of over 6,000 men enrolled in a health program. The men's ages ranged from 19 to 60, with the average being 40. They were asked about smoking habits and estimated time spent working, exercising and watching television. Both their level of fatness and fitness were measured.Most subjects watched one to two hours of TV a day. Younger men, the less fit, smokers and those who did not exercise watched more. Obesity or super-obesity was found in one-third of the subjects. After eliminating other factors that could affect fatness level, those who watched three or more hours of television were twice as likely to be obese or super-obese.
The authors of the study suggest three reasons for this: It may be that men who are already overweight are more attracted to watching TV than their slimmer peers. A second possibility is that both obesity and TV viewing are explained by the same factors; physical activity and physical fitness were inversely related to both obesity and television viewing, especially the latter. And it may also be that people who spend more time in front of the tube also consume more calories, although that possibility was not assessed in the study.
But whatever science uncovers in the future about this issue, we all know that time spent watching TV, enjoyable as it may be, is also time that might be better spent in pursuit of fitness and a more streamlined body.
QUESTION - Lured by the fact that it was on sale, I recently tried freshwater catfish. I liked it and plan to buy it again. What can you tell me about its nutritional value?
ANSWER - There are many different species of freshwater catfish, but the most common and the one you most likely had is a variety called channel catfish, or Ictalurus punctatus. This also happens to be the type considered the tastiest. While it is abundant in the Mississippi Basin, the majority is now cultivated.
Being comparatively lean, catfish is low in calories. A 3 1-2 ounce serving provides just 115 calories and only 4 grams of fat-a bit less than a teaspoon of oil. It also provides protein of excellent quality, some B vitamins and assorted minerals.
Saltwater catfish, including both ocean catfish (sometimes called wolffish) and sea catfish, nutritionally differ little from the freshwater varieties.
QUESTION - My husband claims he heard on the radio that low blood cholesterol levels have been linked to greater likelihood of stroke. Is it true and, if so, does that mean it's dangerous to lower one's cholesterol?
ANSWER - Hold steady. Such a relationship has been reported recently, but it in no way suggests that you should abandon efforts to lower cholesterol.
The study that your husband heard about examined deaths from stroke in a group of nearly 351,000 men considered for enrollment in the MRFIT intervention trial, designed to evaluate approaches to reducing risk of heart attack. The investigators examined information from death certificates of the men who had died six years later and compared this with data obtained as the men were evaluated for possible participation in the trial.
They did find that risk of stroke caused by hemorrhage in the brain was higher in men with lower cholesterol levels. But that's not the whole story. First, this risk was confined to men with elevated diastolic blood pressure, a group in whom this type of hemorrhage is relatively common.
Second, the increased risk was observed only among men with extremely low cholesterol levels, 160 mg. per deciliter of blood-well below average cholesterol levels in this country. Moreover, the inverse relationship between blood cholesterol levels and risk was limited to only one type of stroke. For other types, either no relationship was found, or risk increased as cholesterol levels rose.
These findings need further investigation. But if you're wondering whether there's a risk trade-off in trying to lower serum cholesterol: The answer is no. The figures tell it best: In this study, after taking age into account, the death rate for hemorrhagic strokes in the brain was 2.36 per 10,000; for strokes not caused by hemorrhage (and not associated with lower blood cholesterol levels), it was 2.62 per 10,000.
For coronary heart disease, where the link between higher blood cholesterol and increased risk is well-documented, the death rate was 60.5 per 10,000, many times that from strokes of any type.