Calorie Counts Often Too Low on Fast Foods and Frozen Dinners

If you're 50 or older — watch out

The bottom line? If you're over 50 and watching your calories, you should assume that the calorie counts in restaurant foods and packaged foods are higher than what is stated on the label or menu, Roberts says.

Cutting back on calories isn't just about staying svelte — research has shown that eating less can help individuals live longer and may even help ward off age-related illnesses.

Other traps for 50-plus men and women

Hidden calories sneak into our diets in other ways, too, says Dee Sandquist, spokesperson for the American Dietetic Association. The main source of calories we don't realize we're eating is large portion sizes, she says.

"After the age of 40, we need fewer calories every decade," she says. "But a lot of people, especially those in their 50s, have not yet reduced portion sizes." As we age, Sandquist says, we have fewer discretionary calories — calories we can consume beyond the number of calories we need to simply maintain our current weight. For most of us, it's about 100 calories per day on average, depending on our activity level and other factors, such as how much lean muscle you have. That 100 calories can equate to the after-dinner cookie we're used to grabbing or the extra sausage link at breakfast.

Controlling our weight as we age is vital, Roberts says, adding that her laboratory is conducting one of three National Institutes of Health-funded studies on whether human calorie restriction improves benchmarks of longevity. Though the results aren't yet in, Roberts says there's no question that avoiding weight gain as we get older is "enormously helpful" in preventing age-related illnesses such as heart disease, type 2 diabetes, high blood pressure and others.

For weight loss, older trumps younger

And, she says, older people tend to do better at losing weight.

"Successful weight loss requires some organization and planning," Roberts says — something with which older adults have a lifetime of experience. Their lives tend to be more settled, she adds, making meal planning and keeping healthy foods in the house easier.

Dara Chadwick writes frequently about health and wellness.