Most weight gain in adulthood results when you consistently consume more calories than you burn. Even 100 extra calories per day can lead to a 10-pound increase in weight over the course of a year. Where you store that fat depends on your genetic body type, which is usually dictated by your gender and hormones. Women especially tend to gain weight in their lower body -- specifically in their hips, thighs and buttocks.
Women are More Likely to Gain Lower Body Fat
Women are more likely to gain weight in the lower body than men, who tend to store excess pounds in the belly. Extra weight accumulates in the pelvis, thighs and buttocks due to female hormones. This fat storage supports child bearing and breast feeding. As young children, boys and girls tend to have approximately the same amount of fat, distributed evenly, but as puberty strikes, women gain fat at a much faster rate than men. By age 25, women have about two times the amount of body fat that men do. Girls usually gain the bulk of this fat in the hips, thighs and buttocks -- and some also in the breasts. After the teenage years, you don't normally acquire new fat cells. The cells you do have expand as they store any excess calories you consume.
Lower Body Fat Is Healthier
Although you may not like the cosmetic aspects of lower body fat, carrying weight there is preferable to carrying it deep in your belly. Deep belly fat has metabolically active properties that increase your risk of chronic disease, such as cardiovascular disease and type 2 diabetes.
The fat you can pinch in your lower body is subcutaneous, meaning it sits just below the skin. It pumps out more beneficial compounds, which include leptin, a hormone that helps diminish your appetite and encourages your body to metabolize stored fat. Subcutaneous fat also produces the hormone adiponectin, which helps you process fats and sugars efficiently so you are less likely to develop diabetes. Subcutaneous fat also offers anti-inflammatory benefits to blood vessels.
If you've passed puberty and are still gaining fat in your lower body, it's likely that you're eating more calories than you burn on a regular basis. The fat cells in your lower body swell to store the surplus of energy. Just 100 extra calories per day can cause you to put on more than 10 pounds a year. If you add a soda, an ounce of cheese, a latte or about 3/4 of an ounce of chocolate to the calories you already eat, you may gain weight.
If your job has you glued to your desk more often than usual, this decreased activity reduces the number of calories you burn daily and can cause weight gain. Working extra hours so you miss the gym or skipping a lunchtime walk are other possible causes of an increase in weight.
Weight gain not related to a change in your diet or activity level might be a result of changing hormones as you age. If you're concerned, talk to your doctor about other possible causes.
Losing Lower Body Fat
Subcutaneous fat is a preferable type of fat to have, but if the amount you have puts you in an unhealthy weight category according to your body mass index or a doctor's evaluation, you need to lose some fat. You can't target specific areas for fat loss, though. If you're a pear shape -- smaller up top with a heavier lower body -- when you lose weight, you'll just become a smaller pear. Your general body shape can't change with weight loss, but will shrink proportionately.
Subcutaneous fat, especially on the lower body, is hard to lose, but will eventually respond to a classic strategy of eating less and moving more. A 500 to 1,000 calorie deficit per day created by burning more calories and reducing what you eat yields a loss of 1 to 2 pounds per week. Easy ways to cut calories include limiting sugary drinks and treats, and choosing fruit or yogurt for snacks instead of processed chips or snack crackers. A 30- to 45-minute brisk walk or session on the elliptical trainer could help you burn more calories. Alternatively, add small movements all day long, such as climbing the stairs instead of using the elevator, pacing while on the phone and performing household chores.
You Can't Spot Train Lower Body Fat
Squats, lunges and leg lifts strengthen and sculpt the muscles of your lower body, but don't directly burn fat from the region. You simply can't target a region from where you'll lose that fat. Your body mobilizes fat stores from all over your body to use as energy, not from the specific place you're exercising. You're more likely to prompt weight loss all over your body with regular cardiovascular exercise that burns calories and thus raises your calorie deficit.
Although you can't target your lower body fat, strength training every major muscle group improves your body's ratio of lean mass to fat mass. The more lean mass -- especially lean muscle mass that you have -- the faster your metabolism burns, making weight loss easier.
Also note that the place you gain weight first -- for women, that's usually the lower body -- is the place you lose weight last. The lower body is thus a well-known "trouble spot," but with concerted exercise and healthy eating, you can slim down to a healthy size.