I’m getting fat — in all the wrong places!

Welcome to the updated Health section of Today.MSNBC.com, the "Today" show’s Web site! I’m Judith Reichman, M.D., the show’s medical contributor on women's health. I hope to address your questions and concerns in my weekly column, so please e-mail me. Meanwhile, you will find many answers to your questions in my latest book, "Slow Your Clock Down: The Complete Guide to a Healthy, Younger You," published this month by William Morrow, a division of HarperCollins.

A: Blame it on female hormones.

To begin, women have a higher body-fat percentage than men — 22 to 28 percent, versus 15 to 20 percent. This process begins during puberty, when estrogen levels rise.

In addition, if you have been pregnant, placental hormones increase your appetite and foster fat accumulation. This provides nutrition for the developing fetus and allows for the production of breast milk (which contains 50 percent fat).

And it doesn’t end there. Beyond your reproductive years, you are likely to keep gaining weight, partly because there is a four to five percent decrease in your metabolic rate every decade. There’s also a decrease in energy-using muscle cells and an accompanying accumulation of not-so-attractive fat cells.

All this adds up — the average American women gains 0.8 lbs a year between 25 and 50. That adds up to a hefty 20 lbs.

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Where that fat goes also changes. Our shapes evolve from stylish pears into dumpy apples. Fat gets deposited under the abdominal wall and — voila — your waistline disappears.

An overabundance of this “visceral fat” is medically dangerous. It leads to changes in glucose processing and increases insulin resistance. This sets women on the road to all sorts of ailments — type II diabetes, heart disease, cancer, gall-bladder disease, osteoarthritis, sleep apnea.

What to do? The only ways to lose weight permanently are to burn more calories or take in fewer (or, better yet, a combination of the two). How you go about this is a matter of choice, depending on taste, economics and common sense.

Bear in mind: It takes time to gain weight, so give yourself time to lose it. Aim for no more than two pounds a week.

For long-term weight loss, my advice is not to go on an Atkins-style diet, which is unhealthily high in protein and saturated fat. You can use it for a jump start, but limit it to three months.

This type of diet omits complex carbohydrates, which are important for health. (Women who consume lots of fruits and vegetables are less likely to get obese than those who don’t.) Too much protein leads to osteoporosis and kidney damage, and too much saturated fat may indeed saturate your heart with fat.

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When it comes to exercise, you should be doing both aerobic exercise and weight-resistance exercise. (On March 23, during our weeklong “Slow  Your Clock Down” series, we will be talking about an exercise program.)

You need not sweat to burn calories, nor do you need a gym. Fun activities like ballroom dancing, biking swimming and golf will do it. But you a have to carry your clubs!

As the weather clears, everyone should be able to do energetic walking. In bad weather, hit the mall. Consider this example: A 200-lb woman who walks a brisk 1.5 miles every day (without changing her eating patterns) will lose about 15 lbs in a year.

And many exercises requires little concentration or focus — I do the treadmill in front of the tv or while watching a video.

• Dr. Reichman’s Bottom Line: Think positively — little things add up to big results. Every time you don’t eat a sundae, every time you go for a walk with Fido (or, in my case, with Lucy), remind yourself how glad — and fit — you will feel tomorrow.

Dr. Judith Reichman, a regular “Today” show contributor, has practiced obstetrics and gynecology for more than 20 years. Her latest book, "Slow Your Clock Down: The Complete Guide to a Healthy, Younger You," is published this month by William Morrow, a division of HarperCollins.

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