A 2002 report from the National Academies' Institute of Medicine, recommends that people get one hour of physical activity a day. This is up from the half hour recommended in a 1996 surgeon general report. The activity may be from many sources, such as walking gardening, playing tag, Taekwondo, etc. and it may be done in increments that add up during the course of a day. The report also says the best diet for minimizing the risk of chronic disease is one that get 45% to 65% of calories from carbohydrates, 20% to 35% from fat, and 10% to 35% from protein. The daily intake for fiber should be 38 grams for men and 25 grams for women in the ages 50 and under. For men over 50, it is 30 grams, and for women over 50, it is 21 grams. The minimum daily intake of carbohydrates for adults and children should be 130 grams. No more than 25% of total calories should come from added sugars. Saturated fat (found in meat and high-fat dairy products), cholesterol, and trans fatty acids (found in cookies, cakes, and processed foods) should be kept as low as possible.
A 2002 study by Duke University of 111 sedentary, overweight men and women found that even modest exercise may benefit the heart by making cholesterol less damaging to the heart, even if the cholesterol level is unchanged. Previous research showed that exercise does not lower the dangerous LDL form or cholesterol and that only rigorous exercise can raise HDL, the good form. Cholesterol spreads through the body by attaching to protein particles. Cholesterol seems more likely to clog arteries when it is called by small dense protein particles than when it is carried by large fluffy ones. The study found that people who exercise develop these large protein particles. Good effects were found in subjects who either walked or jogged 12 miles a week while effects in those who jogged 20 miles a week were even more pronounced.
A 2002 study by the University of Ulster in Northern Ireland found that 10 minutes of exercise three times a day was just as effective as one 20 minute session. They found that the short bursts were also great for improving mood. This is good information for people who are just starting an exercise program.