Three months before my wedding, I had a realization: I don’t want to be a fat groom.

My 5’9” frame tipped the scales at 231 pounds, easily qualifying me as obese — a designation that advanced my biological age of 26 by 2 decades, according to a UCLA study.

More disturbing, a blood test showed that I was on the verge of diabetes, despite having no obvious symptoms (other than a bulging belly).

But dramatic change doesn’t take as long as you might think. In 12 weeks, I lost 33 pounds and whittled 5 inches off my waist — just in time for our big day. Like most overweight men, I wasn’t proud of carrying around all that extra flab — especially since I’m an editor at Men’s Health. But it wasn’t until I literally feared for my life that I became fully committed to change.

When I showed up at his office, Dr. Berkowitz first analyzed a blood test I’d had done in preparation for our meeting. My triglycerides — a measure of the fat circulating in my bloodstream — were more than double what’s considered normal. Chances are, if you’re overweight, your blood work may look similar. Research shows that heavier men have higher cholesterol, triglycerides, and blood pressure than their leaner counterparts.

Much to my horror, Dr. Berkowitz recommended a “controlled-carbohydrate diet.” That doesn’t mean cutting out carbohydrates altogether. Rather, you restrict the types that significantly raise your blood sugar and thus your insulin levels — for instance, those found in soda, candy, and foods made with flour. The upshot is that this plan limited my carbs to those found in vegetables and fruit, which was a drastic change from my regular, carbohydrate-laden diet.

While Keith Berkowitz served as general manager of my diet, his wife, Valerie — a registered dietitian and director of nutrition at the Center for Balanced Health — took the job of head coach. She helped me create an eating plan that was user-friendly and required no calorie counting. For the most part, these are foods that are made with sugar or are high in starch, such as bread, pasta, any other flour-based food, potatoes, and rice. Because they all contain high amounts of glucose, they raise blood sugar quickly.

This may be the ultimate diet cliche, but there’s no question it works. In fact, a study of more than 2,000 low-carb dieters found that, on average, the biggest losers were consuming four servings of nonstarchy vegetables a day.

This is especially important at breakfast and with snacks, when guys are most likely to skimp on this muscle-building nutrient. Thanks a lot, cereal.) Case in point: University of Illinois scientists report that, on average, people consume 65 percent of their protein after 6 p.m. That’s right, the kind that’s found in a piece of meat, an omelet, an avocado, olives, or olive-oil-based dressing. Because fat alone doesn’t raise your insulin levels, it has little to do with making you fat, contrary to popular opinion, says Valerie.

Prediet, I lived on lunchmeat. But Valerie nixed these packaged meats quickly, because most contain added salt (affecting weight and blood pressure) and sugar, as well as nitrates, which are associated with an increased risk of cancer. Finish off the flab with this full-body fat-burning routine from Michael Mejia, C.S.C.S., author of The Better Body Blueprint. Warmup: Before each workout, warm up with 5 minutes of light aerobic exercise or calisthenics.

Weight training: Do the weight workout that follows 3 days a week, resting at least a day after each session. Perform the exercises as a circuit, completing one set of 10 to 12 repetitions of each movement before resting for 60 seconds. Stand holding dumbbells overhead with a grip that’s twice shoulder-width. Get into push up position with your arms straight and your hands resting on light dumbbells. Spread your feet apart for balance. Lie on the floor with your arms out to the side, knees bent and feet flat on the floor. Grab a lat-pulldown bar with a “false” overhand grip that’s just beyond shoulder width.

A false grip means you place your thumb on top of the bar, alongside your index finger, rather than wrap it around the bar. Grab a weight plate with both hands and sit on the floor with your knees bent and your feet flat. Hold the weight plate straight out in front of your chest with your palms facing each other. Support your body with the balls of your feet and with your hands, positioning the latter slightly wider than shoulder-width apart, palms flat on the floor. Straighten your arms without locking your elbows.

Cardio: After each weight-training session, finish up with 12 to 15 minutes of aerobic exercise — running, cycling, rowing — using an intensity that you judge to be a 7 or 8 on a 10-point scale.

Yet, for many people, losing weight and keeping it off is a lifelong struggle. Too often, we look for a fast and painless solution.

If you ask 10 people how to lose weight for good, you’d get 10 different answers.

If you count on peer support to meet goals, a program like Weight Watchers might work for you.

If you’re self-driven, you can design your own plans, based on your needs and choices. Scads of diet books and web sites have tools you can use.

No matter how you choose to lose, include a healthy diet and regular physical activity in your plan.

Slow down and look at your lifestyle.

How and when do I eat?

Do I skip meals?

Am I a junk-food junkie?

Do I take time to eat regular, balanced meals?

Do I eat under stress?

Do I eat for other reasons besides being hungry?

Do I drink enough water?

Make a list of your bad eating habits. Then write a plan for how you can change them.

If you don’t know what a healthy diet is, find out.

Find out what your healthy weight should be for your height and frame and how many calories you should get each day.

Check out any weight-loss program before you sign up.

Who runs the program (hospital, wellness center, commercial business)?

What kind of training and experience does staff have?

Does the program make unrealistic promises, like quick weight loss?

Does it have a solid reputation?

Does it have a maintenance program (to help you keep the weight off)?

Does it have written statements of policies, prices, and procedures?

Does it promote or encourage drugs or supplements?

You didn’t gain the weight overnight.

One of the main reasons Americans are gaining weight is that they’re not active enough.

You lose weight by using more calories than you eat (or eating less than you use.) Physical activity helps you burn calories and lose weight. It also can help you keep weight off by building muscle and increasing your metabolism.

A minimum 30 minutes of moderate physical activity at least five days a week is a good way to begin, especially if you’re just starting out or haven’t been active in awhile.

Of course, you can reap even greater health benefits with an hour of daily, moderate physical activity.

Change your lifestyle for good. If you go back to old habits after you’ve reached your weight-loss goal, you’ll gain it back.

Don’t skip meals, especially breakfast.

Drink plenty of water.

Eat bulky foods that are filling and low in calories.

Keep a food journal.

Sometimes we have to try something many times before we succeed. For many people, this is especially true of losing weight for good.

Learn how to eat right for life.

People go through five stages that lead to behavior change.

Snacks don’t need to be fattening.

Healthy recipes, articles on managing weight, and a healthy weight planner await you at this site.

This quick reference chart will tell you if you’re at a healthy weight, overweight, or obese.

Find recipes or visit the support center, body fat lab, or fitness and weight-management directory.

Find these books online at Barnes & Noble.com.

“Fight Fat After 40,”