A “Normal” BMI Can Miss The Harmful Effects of Excess Body Fat

Body Mass Index (BMI) is a standard method for assessing body weight. BMI is calculated by dividing a person’s weight by the square of his height. A study from Israel found that one third of more than 3000 normal-weight and normal-BMI individuals were still at high risk for diseases caused by obesity, such as diabetes, heart attacks, strokes and kidney damage. The researchers used special X-rays called DEXA scans to measure body fat directly and found that one third of the participants were within the normal range of up to 38.5 percent body fat for women and 26.5 percent for men (Front Nutr, June 9, 2023;10:1173488).

This study suggests that doctors should stop using BMI to predict susceptibility for diseases associated with excess fat, because BMIs often do not diagnose body fatness or predict a person’s likelihood to suffer the diseases associated with obesity. It is far more dependable to measure body fatness by checking the thickness of the fat layer under the skin near the belly button (which should be less than three inches), or to use a device that measures the body’s electrical conductivity. A sonogram of the liver can also be used to show whether the patient has a fatty liver.

Fatty Liver Predicts Diabetes
Storing fat in your belly is a stronger risk factor for diabetes than just being overweight (BMC Public Health, November 18, 2019). Most cases of Type II diabetes are caused by the inability to respond to insulin because of excess fat in the liver (J Clin Invest, May 19, 2020). Your blood sugar rises after meals. When blood sugar levels rise, the pancreas releases large amounts of insulin to lower blood sugar by driving sugar into the liver. However, if you have too much fat in your liver, the liver refuses to accept sugar from the bloodstream and blood sugar rises to high levels. Having excess fat in your liver also puts you at high risk for strokes, heart attacks, liver failure, and some cancers. More than 50 percent of people with excess fat in their liver are already diabetic or pre-diabetic (J of Family Med and Prim Care, Dec, 2022;11(12):7640-7643), and 11-20 percent of people with excess fat in their liver will suffer from liver failure within 10–15 years (Clin Gastroenterol Hepatol, 2015;13:643–540).

Signs of a Fatty Liver
You are at very high risk for a fatty liver if:
• You have a big belly and small buttocks. Men are at increased risk for having a fatty liver and being diabetic if their waist circumference is greater than 38.7 inches, and women if it is greater than 36 inches. Measuring a person’s waist circumference is a simple and efficient way to see if people who are not overweight are still at increased risk for diabetes (Arch Med Sci Civil Dis, July 22, 2019;4:e64–e71).
• You can pinch more than two inches of skin and fat next to your belly button, even if you are thin everywhere else
• A sonogram demonstrates a fatty liver
• Your blood sugar one hour after eating a meal is greater than 145 mg/dL. You are probably already diabetic, even if your fasting blood sugar is normal (under 100 mg/dL)
• have a high fasting blood sugar (>95)
• have high triglycerides (>150)
• have low good HDL cholesterol (<40)
• have a high HBA1C (>5.5), a test that shows how much sugar is stuck on hemoglobin

Treatment for a Fatty Liver
• Avoid foods that cause a high rise in blood sugar, such as all sugar-added foods and all drinks with sugar, including fruit juices. Restrict other refined carbohydrates, such as foods made from flour. Most people with a fatty liver are overweight and will need to lose weight to get the fat out. Eating a plant-based diet that restricts refined carbohydrates (such as bakery products, pastas and most dry breakfast cereals) and foods with added sugar helps people to reduce the amount of fat in their liver, decrease insulin resistance and lower triglycerides and cholesterol (Metab Syndr Relat Disord, 2019;17(8):389-396).
• Exercise can markedly reduce the amount of fat in your liver (World J Gastroenterol, Jul 21, 2016;22(27):6318-27). It does so by lowering blood sugar which then lowers triglycerides, the fat that forms in your liver (J of Funct Morph and Kines, 2017;2(4):35). Exercise reduces liver fat even if a person does not lose weight (Metabolism, Mar 2017;68:119-132).