While it isn't healthy to be overweight, if you slim down too much, you may lose enough fat from your face so that it becomes less full. More hollow cheeks and a slimmer chin can sometimes age a person's face and seem to accentuate tiny wrinkles, which most people would prefer to avoid. It isn't always possible to avoid losing any of the fat that gives your face its shape, however.
Facial Fullness and Spot Reduction
As much as you might like to choose which part of your body loses fat, it just isn't possible, according to the American Council on Exercise. To prevent losing fullness from your face, you can't choose which part of you doesn't slim down either. Exercising one part of your body to the exclusion of others doesn't take weight from that body part. For example, even when men did a total of 5,004 sit-ups over the course of 27 days, they lost about the same percentage of fat from their shoulders and rear ends as from their stomachs, reported a classic study first published in Research Quarterly for Exercise and Sport in 1984.
Location of Fat Loss
When you lose weight, you don't actually lose fat cells; the cells just shrink. Weight loss typically causes proportional fat losses all over your body, which means you lose the most fat from the area in your body where you store more of it. Thus, you'll tend to have the same body shape even after you lose weight, but you'll be a bit smaller all over. People also usually lose fat first from the last place they gained it. Therefore, if you had a thin face that became rounder as you gained weight, you might lose the plumpness from your cheeks first when you slim down again.
Gender Differences in Fat Storage
In general, most women tend to accumulate fat around their hips and thighs, while men tend to put on more fat in the abdominal area. Stored fat in the hips and thighs, which stems from the female sex hormones, is considered sex-specific fat. A fat store may be helpful during pregnancy; the body tends to hold onto that fat and prioritize fat loss in other areas, such as the abdomen, chest, arms or face. As a result, you may not be able to lose fat from your lower body without giving up some of the fullness in your face.
Potential Benefits of Exercise
You probably realize that exercising can help speed up weight loss, but it also has other benefits when you're trying to lose weight. For example, resistance training helps build and tone your muscles so you look more fit as you drop the pounds. Strength training also helps ensure that most of the weight you're losing is fat instead of lean tissue. What may be particularly helpful for people trying to maintain fullness in their face is that weight loss caused by exercise may be less likely to come from the face than weight loss through diet alone.
Weight loss resulting from exercise appears to preferentially target abdominal fat, according to a study published in Medicine and Science in Sports and Exercise in 2003. Do your best to fit in at least two resistance-training sessions and 300 minutes of moderate-intensity cardio each week. You'll know you're exercising at a moderate level when you can talk, but not sing, without becoming breathless, while exercising.
Choosing Your Weight Loss Goal
The more fat you burn, the more likely you are to lose the fullness of your face. For each height, there's a range of weights that are considered healthy. You may not want to aim for a weight on the lower end of the range if you're worried about your face becoming too thin. For a person who is 5 feet, 5 inches tall, a healthy weight is between 114 and 144 pounds, and, if you're 5 feet, 9 inches tall, it's 128 to 162 pounds. Talk to your doctor about your healthy weight range; then set your goal somewhere in the mid- to high-end of the range to increase your chances of keeping some facial fullness.