But another 120-pound person may have a lot less lean mass and more body fat and therefore a “slow” metabolism. In fact, it is possible to have “normal-weight obesity” – a term used when referring to a person who appears thin but who is not very active and therefore has very little muscle mass, Majumdar explained.
A slow metabolism burns fewer calories, which means more get stored as fat in the body; that's why some people have difficulty losing weight by just cutting calories. A fast metabolism burns calories at a quicker rate, which explains why some people can eat a lot and not gain extra pounds.
The higher your metabolic rate, the more calories you burn performing these chemical processes. A fast metabolism can help with weight loss, as it means you can eat more calories while still burning fat and dropping weight. But having a slow metabolism isn't necessarily a bad thing.
You might want to blame a medical condition for slow metabolism and weight gain. But rarely does a medical condition slow metabolism enough to cause a lot of weight gain. Conditions that can cause weight gain include Cushing syndrome or having an underactive thyroid gland, also known as hypothyroidism.
Factors that may increase a person's metabolic rate include consuming an appropriate number of calories, favoring protein over carbohydrates and fat, getting enough sleep, and some types of exercise, such as resistance training.
Hormonal metabolism tests are the only type you can do at home. Other tests can provide more and different information based on a larger blood sample, but they require you to go to a lab or work with a doctor first. Your doctor can prescribe a metabolism test and perform it in a medical setting.
Hormones
A shift in your hormones can put the brakes on your body's energy use. That can make you tired. Some conditions, like an underactive or overactive thyroid and diabetes, are hormonal diseases that affect your metabolism. Stress also releases hormones that can trigger a slow-down.
Over time, studies have shown that metabolic rate (how fast we burn calories) starts to slow down by 2 to 3 percent each decade, beginning in our 20s. It becomes more noticeable between ages 40 and 60.
Muscle is denser than fat, and as it is more compact within your body, as you gain muscle mass, you end up looking thinner, no matter your physical weight. So, if you've been doing a lot of strength training lately, it's likely this is the reason that you're looking fantastic but not dropping those numbers.
Unintentional weight gain occurs when you put on weight without increasing your consumption of food or liquid and without decreasing your activity. This occurs when you're not trying to gain weight. It's often due to fluid retention, abnormal growths, constipation, or pregnancy.
Hummingbirds, with their tiny bodies and high levels of activity, have the highest metabolic rates of any animals -- roughly a dozen times that of a pigeon and a hundred times that of an elephant. To maintain those rates, hummers have to consume about their weight in nectar daily.
Metabolism is partly genetic and largely outside of one's control. Changing it is a matter of considerable debate. Some people are just lucky. They inherited genes that promote a faster metabolism and can eat more than others without gaining weight.
A simple breathing test called a metabolic rate analysis can provide a wealth of information about how efficiently your body converts what you eat into the energy necessary to function. The breathing test takes about 10 minutes, and you can't eat, exercise, or drink caffeine for at least four hours before the test.
Weight loss
A study published in 2003 found that switching from drinking cold water to hot water could increase weight loss. Researchers found that drinking 500 ml of water before a meal increased metabolism by 30 percent. Raising water temperature to 98.6 degrees accounted for 40 percent of the increase in metabolism.
Water is the key to life, and it turns out it's also one of the easiest ways to help your metabolism. Drinking water increases your metabolism by up to 25% for nearly an hour after drinking it. That means if you drink a few cups of water every hour, you'll keep your metabolism at peak performance all day.
Eating more often can help you lose weight. When you eat large meals with many hours in between, your metabolism slows down between meals. Having a small meal or snack every 3 to 4 hours keeps your metabolism cranking, so you burn more calories over the course of a day.
Be patient
It may take you some time to increase your metabolism — three months is a reasonable timeframe to expect to see changes. If you are having a hard time losing weight, you might consider having your metabolism tested by a professional nutritionist.
The bottom line
Study findings suggest that we burn calories the fastest in our first year of life, steady down to our “normal” rate by our 20s and stay that way into our 50s.
White men reported the highest levels of PA of the four race-gender groups, whereas African-American women reported the lowest levels.
Your metabolic rate peaks in your early 20s, according to Women's Health Magazine. At this age, you tend to have a higher muscle mass and have a fair amount of physical activity built into your day. As early as age 30, however, men and women begin noticing a dip in their ability to lose weight.
As a general rule, people need a minimum of 1,200 calories daily to stay healthy. People who have a strenuous fitness routine or perform many daily activities need more calories. If you have reduced your calorie intake below 1,200 calories a day, you could be hurting your body in addition to your weight-loss plans.