How Healthy Are You? The Truth About BMI, Body Fat, and Diet

The scale isn’t your only tool in determining how fit and healthy you are. Other measurements, like body fat percentage, waist circumference, and BMI tell as much or more about your overall health and fitness picture as the number on the scale. Here’s the best news: All of these can be improved on a plant-based diet.

If you’ve ever tried to lose weight, you know how obsessed with the scale you can become. Yet while knowing your weight can be a useful tool, it only gives you a fraction of the story. Other measures like body mass index (BMI) and waist circumference, both of which are tied to body fat, play into this as well. Here’s the scoop on what each of these measurements indicate, how you can check them at home, and why you should eat even more plants to improve all of them.

The skinny on measuring your body fat

How many times have you heard people refer to fat as a four-letter word? Maybe you’ve even said the same. Here’s the catch: When people say this, they’re usually referring to the “pinch an inch” type of fat, essentially the kind that sits right under your skin. Yet subcutaneous (or surface) fat isn’t the big issue. Instead, you need to direct your attention to two other types of fat in your body, namely visceral and intramyocellular fats which sit deeper and cause more harm.

While intramyocellular fat are essentially fat droplets stored in muscle cells, visceral fat is the fat in your belly, around your waist and around your organs, and both lead to poor health. “Increase in intramyocellular fat leads to insulin resistance that can cause a myriad of problems, diabetes included,” says Kim Scheuer, M.D., plant-based lifestyle medicine physician and founder of DOKS Lifestyle Medicine in Aspen, Colo. Meanwhile, visceral fat is even more indicative of disease, as it causes inflammation in the body which is paramount to heart disease and many other chronic diseases.

So how can you check your body fat? There are several ways, including the gold standard of hydrostatic weighing where you’re dunked underwater while holding your breath, DXA which is similar to bone testing, and skinfold calipers that pinch the fat you can squeeze. Yet there are drawbacks to each. The first two require special equipment while the calipers check only subcutaneous fat and aren’t that accurate, Scheuer says.

Fortunately, there are ways you can keep tabs on your body fat at home, and the first is BMI. While BMI has come under fire as less than ideal as a way to gauge the population, many experts still consider it a useful tool. “BMI is an excellent indicator, as it’s practical and easy to determine, and it reliably correlates with the percentage of body fat and body fat mass,” says Charles Elder, M.D., internal medicine physician in Portland, Ore.

To determine your BMI, divide your weight (in kilograms) by your height (in meters) squared. If you know both, you can use a BMI calculator to do the match for you. In general, a BMI of 18.5 to 24.9 is considered normal, 25 to 29.9 is overweight and 30 or higher is considered obese, Scheuer says.

Yet because BMI may overestimate the degree of body fat in people who are technically overweight but have a lot of muscle mass, such as athletes or bodybuilders, you should also measure waist circumference. “Increased waist circumference, which assesses abdominal obesity, has been shown to be a predictor of cardiovascular complications and provides useful additional information beyond just BMI,” Elder says. Measure this at home by placing a measuring tape around your middle, just above your hipbones. If you're a man and have a waist circumference of 40 inches or you’re a woman and have a waist measures of 35 inches or more, you’re considered at risk of having heart disease and other issues, Scheuer says.

How a plant-based diet can help lower BMI, raise fitness and health

When it comes to maintaining a leaner physique, plant-based eaters typically have always had the leg up in this department. Numerous studies suggest that plant-eaters have lower BMI than their meat-eating counterparts, including a smaller waist circumference, and lower body fat. The studies also indicate that a strategy to lose weight is to adopt a plant-based diet.

What’s the magic? Simple: “The more whole-food, plant-based you eat, the more nutrient-dense ... your diet will be, so that you’ll lose more fat and weight overall,” Scheuer says. Eat a low-fat diet, and you’ll do even better. She quotes John A. McDougall, M.D., founder of the McDougall Program and Dr. McDougall’s Right Foods, who’s famous for saying that the fat you eat is the fat you wear. That’s because while fat has nine calories per gram, whereas carbohydrates and proteins have just four calories per gram. As a result, plant-based foods, most of which are low in fat, are much less calorie-dense than meat, cheese, and other animal products. Yet because the meat and dairy both lack fiber, these calorie-dense foods are easy to eat faster and thus lead you to overeat, Scheuer says.

Eat more plant-based foods to burn fat, lose weight and get healthier

Plant-based foods like vegetables, fruits, legumes, and grains also have other ways in which they aid your physique. They’re rich in water and fiber, both of which fill you up, and they feed good gut bacteria, which improves satiety and helps boost metabolism, Scheuer says.

And while most animal foods consist of long-chain fatty acids, which promote fat accumulation and insulin resistance in the body (which signals your body to store fat to be used later), plants have higher levels of short-chain fatty acids, which help your body burn fat for fuel. “Short-chain fatty acids help increase fat burning for energy and are associated with many other health benefits,” Elder says.

Want to improve BMI, waist circumference and carry around less body fat? Make sure you’re loading your plate with as many plants as possible, knowing that going 100 percent plant-based is healthiest for you, as well as the planet, and factory-farmed animals, Scheuer says. It’s not just what you eat but when you eat, that matters. “Because your digestion is naturally strongest in the middle of the day at around noon when the sun is highest in the sky, have your main meal at mid-day with a lighter dinner and no snacking at night,” Elder says.

And don’t forget that other lifestyle habits are important too, including exercising daily for 30 minutes or more, reducing stress by enjoying time doing what brings you joy, and logging seven or more hours of sleep at night. Another strategy that works to lower BMI, fat and overall weight: Try limiting the hours you eat (Scheuer recommends stopping eating at 7 p.m.), and drinking plenty of water. Shoot for two glasses of cold water before breakfast, lunch and dinner, she adds. Then know that you've done everything you can to be your fittest, healthiest self.