Your health: The need to trim calories

The right diet

The reality is that when it comes to shedding pounds, the key is cutting calories — and it doesn't really matter whether those calories come mainly from steak, bread or vegetables, according to Harvard Medical School.

A study led by Harvard researchers published in 2009 in the New England Journal of Medicine compared four different low-calorie diets (high fat, high protein; high fat, average protein; low fat, high protein; and low fat, average protein) in 811 overweight adults. Although all the participants lost an average of about 13 pounds in the first six months, they started to regain at the one-year mark. After two years, average weight loss was the same in all groups.

An earlier study in the Journal of the American Medical Association suggested that it's whether you stick with whatever diet you choose that makes the difference.

Experts advise people to keep the percentage of their calories from major nutrients within the recommended federal guidelines:

• Protein: 10 percent to 35 percent

• Carbs: 45 percent to 65 percent

• Fat: 20 percent to 35 percent

Note that diets that are less than 45 percent carbohydrate or more than 35 percent protein are hard to follow, and they're no more effective than other diets. In addition to possibly increasing the risk of heart disease, diets with very low carbohydrate levels may have a negative effect on mood.

The take-home lesson is that it is OK to experiment on yourself. If you give a diet your best shot and it doesn't work, maybe it wasn't the right one for you, your metabolism or your situation.

Day care exercise

A new study in Pediatrics, the journal of the American Academy of Pediatrics, reports that many children in day care do not get the exercise they need.

The Pittsburgh Post-Gazette reports that researchers, headed by Kristen Copeland of Cincinnati Children's Hospital Medical Center, found that children in day care spend only 2 percent to 3 percent of their time in vigorous physical activities.

“This is particularly concerning, because daily physical activity is not only essential for healthy weight maintenance, but also for practicing and learning fundamental gross motor skills and socioemotional and cognitive skills,” the researchers said.

The study indicated that day care may be the only chance preschool children have to play outdoors and join in physical activity.

“Because many of the children were in care for such long hours, there was little free time for outside activities,” the researchers said.

In its previous issue, Pediatrics published a clinical report on the importance of play in healthy child development.

“Play is essential to the social, emotional, cognitive and physical well-being of children,” concluded the report, written principally by Regina M. Milteer, a pediatrician in Fairfax, Va., and Kenneth Ginsburg, a pediatrician at Children's Hospital of Philadelphia.