×

A year after weight loss, the desire to eat grows

  • A bigger challenge than losing weight is keeping it off for more than a year. (Dreamstime) Dreamstime



Los Angeles Times
Friday, February 02, 2018

Losing weight is, for most people, the easy part. The bigger challenge is trying to keep it off for more than a year.

New research helps explain why people in this second stage are so much more prone to failure.

In a nutshell, people who have shed a significant chunk of their weight are hungrier and have a stronger desire to eat for at least a year after transitioning from weight loss to weight-loss maintenance. And even when their hormones send loud satiety signals to the brain after a meal, they still don’t feel full.

The new study, published Thursday in the American Journal of Physiology-Endocrinology and Metabolism, falls in line with a growing field of research that explores the body’s tenacious and multi-pronged response to weight loss.

To study the effects of weight loss in 35 severely obese subjects, Norwegian researchers helped them lose close to a tenth of their weight. They provided dietary advice, exercise coaching and psychotherapy during several three-week stays at a wooded retreat in eastern Norway. All the subjects had a body-mass index greater than 42 (a BMI over 30 is considered obese) at the outset of the study.

At one year, when subjects had lost an average of close to 24 pounds, they returned to the retreat to map out maintenance plans.

Every six months from enrollment to two years out, researchers checked in to conduct a series of tests. Before and for three hours after meals, they gauged subjects’ subjective feelings of hunger, fullness and desire to eat, and asked how much food they planned to consume. And they measured circulating levels of five separate hormones that regulate appetite to see how they responded to the prospect of a meal or a meal just eaten.

What they found was the body’s reaction to weight loss shifted over time.

In the short run — four weeks after their exercise-and-weight-loss regimens got underway — the subjects had lost an average of 3.5 percent of their body weight. Their levels of appetite-boosting hormones had risen rapidly — probably a response to their getting roughly 3½ hours of exercise per day while at the retreat.

But they did not report increased hunger or desire to eat. And with rising levels of satiety hormones, they were feeling more full in the wake of eating a meal.

As they met their weight-loss goals, however, things changed.

At the end of a year of dieting and exercise, the study’s participants had lost about 7.4 percent of their weight and had improved their fitness considerably. But they reported to researchers a significant increase in their hunger and desire to eat. And the sensations of fullness they reported after meals had plummeted.

The good news, according the researchers: A sustained and supportive program of dietary restriction and physical activity does induce weight loss and can help very obese patients keep the weight off.

The bad news: “Patients with severe obesity who have lost significant amounts of weight ... will have to deal with increased hunger in the long-term.”