When I was in medical residency, more than thirty years ago, I ran with a pack of fellow residents, all guys who were fit to varying degrees. Once, on an outing, we discussed the — hopefully — hypothetical question: “If the need arose, which one of us would we eat first?”

“Randy!” my friends gleefully concluded.

“His meat would be the most marbled,” one added.

I’ve never been fat. More accurately, my body mass index (BMI) has never put me in the “obese” category by exceeding the 95th percentile. But I have dwelled in the “overweight” category, between the 85th and 95th percentiles, for some time. I stand close to 6′ 1″, and since college my weight has ranged from the mid-180s to the low 200s, in recent years reaching a peak of 218 pounds.

Staying fit has never been a problem; I have always factored some form of physical activity into my daily routine. I exercise like a fiend — but I also eat like one.

During my residency, whenever my girlfriend’s sister invited us to dinner, she’d ask my girlfriend to “pre-feed” me. And when I traveled to Armenia on a medical mission, my host told me, admiringly, that I ate “like an Armenian.” I don’t mean to slander Armenians, merely to say that my appetite impressed at least one.

How I could eat! And what I used to be able to eat!

Well into my fifties, I ate chips, crackers, bread, cheeses, salamis, ice cream, cookies, chocolate, alcohol — all the basic food groups. Large portions, second and third helpings … you name it, I devoured it with abandon. Occasionally I’d gaze wistfully at those who remained slender seemingly without effort, but my zest for food and drink always overshadowed other considerations.

Over the past decade, though, my blood-sugar levels began creeping up — a sign that I would pay for my overindulgence by joining the legions of people with type 2 diabetes.

Seeking to avert this, I flailed about. I tried to increase the amount and intensity of my workouts and paid lip service to dietary restraint. But mostly I indulged in wishful (even magical) thinking, attributing any weight gain to increased muscle mass from all that working out.

I also incurred the anxiety of my partner, Heidi, and of my mother.

“Can you please make sure he doesn’t eat so much!” my mother, still slender at age ninety, would implore Heidi during our cross-country visits with her. Also anxious was Heidi’s mother — who, though she denies it, greeted me with a pat on the belly when last we met.

To defend myself, and to distract potential critics, I became fond of saying, “Who needs a six-pack when you’ve already got a keg?”

As a primary care practitioner, I know that obesity and its adverse effects on health are a huge — pun intended — problem in this country. I also know that the solution is simple: fewer calories in, more calories out.

But a medical practitioner’s ability to make that happen with any patient is limited. Besides, given my own situation, I’ve often felt self-conscious counseling parents and children about losing weight. In one instance, my efforts prompted a teenage patient to say to his mother and me, “Hey, I think we all could stand to lose fifteen or twenty pounds.”

Then, last year, I noticed an announcement on my hospital’s website, seeking subjects for a twelve-week weight loss study.

What have I got to lose? I thought (again, pun intended). I registered as a subject.

At the initial evaluation, I gathered with seven other potential subjects to learn the study’s particulars, potential benefits and possible side effects. (One was that, as a result of successful weight loss, we might have to reduce or eliminate some of our medications. We wouldn’t want that to happen, would we?)

During my personal evaluation, they weighed me — the number was higher than I’d ever imagined — and gave me a series of cognitive tests measuring characteristics like avidity and impulsivity.

I was given a scale to weigh myself daily. I also received personal diaries to record my daily weight, the foods and beverages that I consumed and the amount of exercise I got each day, and a book that listed the calories and fat in common foods and restaurant meals. (To thank me for coming, they gave me a bag of Cheetos. Go figure.)

During each of the study’s twelve weeks, we subjects would receive an online lesson to help us reach our weight loss goals. The lessons would highlight obvious challenges, such as eating at restaurants or parties, and offer common-sense solutions: eat a low-calorie snack beforehand; take just one slice of bread (or none) before having the breadbasket removed from the table. Further, as a reward, we would be paid for meeting the researchers’ documentation requirements.

Armed with these tools, plus an admonition to consume no more than 1,500 calories and fifty grams of fat per day, and to exercise at least thirty minutes daily, I set out to do the heretofore impossible: to take control of my eating.

Each week I dutifully submitted a table recording my daily weights, calorie and fat intake and minutes of exercise.

I learned a lot. Most importantly, I learned at last, in my sixtieth year, that when it comes to weight and health, the amount and type of food that you consume matters. Duh!

It was a struggle to limit my caloric intake and keep the daily records; frankly, trying to measure and record the exact or near-exact calorie and fat content of foods was a pain in the butt. And limiting my intake, in both quantity and quality, made me feel that I’d entered a more constrained, less pleasurable phase of my life.

Still, I succeeded at meeting the dietary requirements at least half the time, maybe more.

As a result, I achieved my goal: a 10% weight reduction. I reduced my blood-sugar levels to near-normal. Most importantly, I learned the nutritional content of different foods. Who knew that a muffin has 400 to 500 calories — one-third of a whole day’s caloric intake on the weight loss program?

I can’t say that weight loss is easy, but — and this is important — it can be done.

I can say that it feels great to be a healthy weight. It feels great when people compliment me on my physique. It seems inconceivable that I once needed to employ the last notches on my belt to buckle it.

Now I’m in the study’s maintenance phase; I check in every three months. Although I don’t count calories, I pay close attention to what goes into my mouth, and I exercise daily or almost daily. I also weigh myself daily. The process is not anxiety-free, but it’s necessary, as one online lesson put it, “to prevent a lapse from becoming a relapse.”

Some of my pediatric patients — or more precisely their mothers — have commented admiringly on my weight loss. A number, overweight themselves, are eager for me to share my newfound wisdom. And I do, now without feeling conflicted.

But it only matters if I manage to keep the weight off. A year into the study, I am discovering how challenging this can be.

So I stick to the study’s guidelines:

1. eat breakfast daily
2. weigh daily
3. don’t let a lapse become a relapse

By following these, I hope to keep the weight off.

And also, if once again my buddies try to pick which one of us to consume, I hope that I’ll no longer be the first choice.

Randy Rockney is a pediatrician. This article was originally published in Pulse — voices from the heart of medicine, and is reprinted with permission.