It’s easy to get obsessed with personal numbers these days. Put on a wearable like a Fitbit and see what I mean. The devices track your number of steps during the day, gauge your heartbeat, and record the amount of time you’ve slept at night. They can log your walking routes, with maps, and reveal how fast your feet were really moving.

You can sync to an app that records the calories you take in, for more fun with numbers. (Warning: if you’re trying to lose weight, the daily summary may be less encouraging on days you eat more. You might get something like this: “If every day were like today, you’ll reach your goal by April 18, 2022.” No consolation added if your big reunion is six months away.)

Of course, doctors will remind you that losing extra weight isn’t just about wearing a smaller dress size. The big payoff is better health.

In that regard, if you like tracking your progress in losing weight and getting fit, you might want to try using one of the simple health-screening tools that gauge risk for conditions like diabetes and heart disease.

The health-screening methods – that use BMI, waist circumference or waist-to-hip ratio – are based on research that shows body size and shape influences risk of certain diseases.

And they’re pretty simple. All you’ll need to get started is a scale and cloth measuring tape. Once you know where you stand, working toward “low risk” is another goal to strive for.

1. BMI: You’ve probably heard of body mass index, or BMI. The index categorizes people in ranges from normal to super obese. BMI is a formula that includes a ratio of weight and height. The easiest way to crunch the numbers is to use an online BMI calculator, such as this one.

Risk of poorer health goes up for people with BMIs that indicate they are overweight. It climbs higher still for those in the obese category.

A warning, though: For people who are lean and muscular, there may be a hitch. Their BMI can indicate “overweight” or “obese” when they aren’t. This is because muscle weighs more than fat, so their total weight is higher. They aren’t fat, but the BMI formula doesn’t distinguish between toned muscles and flab.

2. Waist circumference: How big is your middle? Where you carry extra weight makes a difference, according to obesity researchers.

It’s a matter of being shaped like an apple or a pear.

The apple-shaped have bellies that are bigger than their hips. Any extra pounds tend to pile up on their waistlines. It’s the opposite for people who are pear-shaped. Extra weight likes to go to their hips and thighs.

Women are more likely to be pear-shaped – until they reach menopause when hormone levels change and weight gain heads for the abdomen.

People who are apples tend to be more at risk for certain health conditions. Their expanded bellies indicate visceral fat. This type of fat lies deeper within the abdominal cavity and has been linked to conditions like heart disease and diabetes.

Optimal numbers are based on gender, and individual height and weight doesn’t matter. Ideally, women need to keep their waists to 35 inches or less. The benchmark for men is 40 inches or less.

A screening chart from the National Institutes of Health combines BMI and waist circumference and shows how an apple shape raises health risks. Look at the chart and you’ll see how a BMI that indicates “overweight” puts you at increased risk. Combine “overweight” with a higher-than-optimal waist measurement and the level jumps to high risk.

3. Waist-to-hip ratio:

The size of your waist in relationship to your hips is another simple screening tool for future health risks.

For instance, a British medical study looked at waist-to-hip ratio and how it relates to heart disease. Have a big waistline and comparably big hips? That could be less of a risk factor than having a big stomach and small hips, according to the study.

Again, it’s about too much abdominal fat. In the study, researchers suggest that abdominal fat might alter hormones in a way that increases risk of heart disease. A large waistline in proportion to hips also has been shown to increase risk of uterine cancer, and has long been linked to Type 2 diabetes.

To determine your waist-to-hip ratio, measure your waistline and your hips. Divide the waistline measurement by the hip measurement – or go online for a waist-to-hip ratio calculator.

Ideally, results should be less than 0.85 for women and less than 0.9 for men, according to the World Health Organization.

Happy tracking!