How Metabolism Affects Body Weight and Disease
If you’re taking in more calories than you’re burning, you will gain weight. The Law of Thermodynamics governs the fact that calories in versus calories out regulates body weight. Not sure what a healthy body weight for your height is? To get a general idea, use the Hamwi Method.
For men: 106 lbs. for the first 5 feet + 6 lbs. for each inch over (+/– 10%)
For women: 100 lbs. for the first 5 feet + 5 lbs for each inch over (+/– 10%)
This means if you’re a 5'5" woman, your ideal body weight range is 125 pounds, plus or minus 10 percent of the total depending on the size of your frame (subtract 10 percent for a relatively small frame, add it for a relatively large frame). If you’re less than 5 feet tall, you can divide the starting number — either 100 or 106 depending on your sex — by 60 inches and then multiply by your height in inches.
Calculating your body mass index or BMI is another general measurement that gives you an idea whether you’re within a healthy weight range:
BMI = (Weight lbs./height inches2) x 703
The BMI calculation is limited mainly because it doesn’t take into account body fat percentage or body shape. If you have a lot of muscle mass, it’s possible you can have a high BMI but not be at risk for increased disease.
Another measurement, the waist-to-hip ratio, can be used to determine the presence of abdominal obesity and also takes into account body shape. Measure your waist at your belly button and divide that by the measurement of your hips around the middle of your buttocks.
A waist-to-hip ratio greater than 0.9 for men or above 0.85 for females is considered abdominal obesity by the World Health Organization. Even in people who are not overweight, a high waist-to-hip ratio can be a risk factor for diabetes, high cholesterol, and high blood pressure.
Type 2 diabetes
About 80 percent of those diagnosed with Type 2 diabetes are overweight or obese. When you’re overweight, it becomes more and more difficult for insulin to regulate your blood glucose levels, so your body starts overproducing insulin. Having too much circulating insulin can slow your metabolism even further, which makes your cells even less receptive to taking up blood glucose, known as insulin resistance.
You can also develop pre-diabetes as your body starts having more trouble regulating blood glucose.
You’re more likely to develop diabetes if you have a family history of it, are older than 40, are inactive, and have high blood pressure. Go to your doctor if you’re experiencing any of these symptoms related to diabetes:
Cuts and bruises that are slow to heal
Fatigue and irritable mood
Carrying too much extra weight also has a negative impact on your circulating lipoprotein and triglyceride levels, which increases your risk for a heart attack, stroke, or other cardiac event.
Your blood pressure increases along with your body weight, which also elevates your risk for heart disease, stroke, and kidney disease. Losing weight can directly result in lowered blood pressure.
This syndrome is one of the fastest-growing obesity-related concerns in America, and it is classified by a cluster of symptoms like insulin resistance, hypertension, and dyslipidemia. According to the National Health and Nutrition Examination Survey (NHANES), almost a quarter of Americans have this syndrome which puts them at a greater risk of developing the preceding diseases.
Polycystic ovarian syndrome (PCOS)
This is the most common hormonal disorder among reproductive-age women. It can result in insulin resistance, which makes it a major risk factor for developing diabetes. Most people who develop PCOS are overweight, and it’s characterized by an overgrowth of underdeveloped follicles in the ovaries which results in irregular menstrual cycles, ovarian cysts, and excessive hair growth.
Obesity is correlated with the development of certain types of cancers, such as esophageal, pancreatic, liver, breast, kidney, thyroid, uterine, and colon cancer. Because overall inflammation in the body is also greater when you’re overweight, your body is primed for the initiation of tumors. In addition, fat cells release more estrogen, lipase, and additional hormones which may increase tumor growth.
Being overweight puts more pressure than necessary on your joints, making movement more difficult, causing the breakdown of cartilage and the potential need for a joint-replacement surgery. When you’re obese, having any type of surgery increases the risk for complications and a longer stay in the hospital.
Being overweight can compromise your respiratory function, making it more difficult to get a good night’s sleep. Not getting a good night’s sleep can in turn increase the risk for obesity, affecting your hormone levels and appetite.