Q: It is often said that Americans waste a lot of food. Have there been studies showing exactly how much homemakers throw away?
A: As you might guess, these studies are difficult to conduct, but they have been done. More than 25 years ago, one group of investigators estimated that 7 percent of the calories brought into the home were wasted. More recently the so-called "garbage-can" project used archeological methods to measure waste. It was found that waste added up to a little over 4 1/2 pounds a week in the average household.
In the latest study, conducted by researchers at the University of Oregon, the average household discarded about 3 1/2 pounds of food a week. This waste was worth around $2.88 a week -- about $150 a year. The figure may be somewhat high, because it does not factor in home-grown produce, which is less expensive. Similarly, nearly 2 ounces of waste falls into the fat category, and is probably accounted for by meat trimmings, which belong in the garbage can.
The Oregon study also looked at why people throw food away. Discard practices varied by age, income and number of children in the household. While some households wasted almost nothing, others threw out up to $1,700 of food each year. In general, householders discarded over a pound of fruits and vegetables a week (not including peels, skins and cores).
Quality factors were the major reason for wasting produce, accounting for 30 percent of that total. About 6 ounces of meat, fish and poultry found their way to the garbage. Thinking the food had been kept too long was the biggest single reason for waste in that category. Plate waste and leftovers together made up over half the waste of 6 1/2 ounces of cereal foods a week. Six ounces of combination dinners were discarded, 40 percent of that because of failure to use them up. Almost 6 ounces of dairy products were tossed, 40 percent as plate waste and 25 percent more attributed to moldy cheese.
The average amounts of food waste may not seem large, but remember that this study was confined to homes. It did not cover food wasted in restaurants and in the many other places.
Q: Is it true that exercise can help prevent osteoporosis ?
A: Physical activity is essential to maintaining health, but whether it is of significant and lasting benefit in building and maintaining bone, slowing age and menopause-related bone loss, or in reducing the likelihood of fractures remains to be demonstrated.
For one thing, identifying clear-cut benefits of exercise is complicated by the enormous variation in type, duration and intensity of exercise programs. Furthermore, the value of conclusions made by researchers is limited by problems in the study designs that have been used. For example, no long-term studies on bone health have factored in the effects of medication, dietary changes or participation in other fitness programs.
Exercise may well emerge as a key player in warding off osteoporosis. But researchers from the University of Southern California who reviewed the current evidence concluded that more study is needed before we can develop clear recommendations for exercise programs to prevent osteoporosis.