The Ultimate Tools to Track Your Body Change at Home

The short answer: if you only buy one thing, get a smart scale that saves every weigh-in to an app, so you see the trend and not just today’s number. Then add an inexpensive body tape. The scale can’t tell fat from muscle or water, so your waist measurement can show change the scale misses.

The other three each track one more piece. A phone tripod gives you progress photos you can compare. A food scale keeps your food log honest. A fitness tracker counts your steps.

None of these tools will change your body by themselves. What they do is show you that your habits are working, which is what keeps most of us going. Want to see where you’re headed first? Try the Body Visualizer, then use these tools to watch the real thing happen.

How to track the right way

• Weigh at the same time, the same way. First thing in the morning, after the bathroom, before you eat or drink, in the same clothes (or none). Food, water, exercise and even skin temperature change what a body-fat scale reads, so keeping things the same matters more than the scale you own.
• Watch the weekly trend, not one day. Weight goes up and down through the week. One study of daily weigh-ins found people were heaviest on Sunday and Monday and lighter by Friday, and called that normal. Compare this week’s average to last week’s.
• Measure your waist once a week. Stand up, wrap the tape around your middle just above your hipbones, and read it right after you breathe out, says the National Heart, Lung, and Blood Institute. A tip: keep the tape flat and snug, but not pressing into your skin.
• Take photos every two to four weeks. Same spot, same light, same time of day, same clothes. Put the tripod in the same place every time (a bit of tape on the floor helps), and take a front, side and back photo. Then look at them side by side.
• Pick a healthy pace. The CDC says people who lose about 1 to 2 pounds a week are more likely to keep it off.

What the numbers can and can’t tell you

• Body fat from a scale is a rough guess. Studies comparing home scales with a hospital DEXA scan found the average across a group comes out close, but one person’s reading can be off by several points either way. Use it to see which way you’re heading, not as an exact number.
• Your waist tells you something the scale can’t. The NHLBI says a waist over 35 inches for women, or over 40 inches for men, raises the risk of heart disease and type 2 diabetes. Watching it come down is a health win even in weeks when your weight doesn’t move.
• Calories burned on a tracker are rough too. A Stanford study of seven wrist trackers found none got calories burned within 20 percent. Steps are much closer: a review of 158 studies found Fitbit, Apple Watch and Samsung counted steps accurately in the lab. So count steps, and don’t “eat back” the calories your tracker says you burned.
• Steps are worth counting. A large US study followed adults aged 40 and up. Those who took 8,000 steps a day had about half the risk of dying during the study as those who took 4,000. It shows a link, not proof, but it’s a good daily goal.
• Guessing food portions usually comes out low. In a study of almost 1,900 adults at fast-food chains, people guessed their meal had about 175 fewer calories than it did, and bigger meals had bigger gaps. Weighing your food takes the guessing out of your food log.

How often should you weigh yourself?

Weekly works about as well as daily, a review of weight-loss studies found. Choose what feels good to you. In one six-month trial of 91 adults trying to lose weight, daily weighing didn’t harm mood or eating habits. But some research links frequent weighing with lower mood and self-esteem in women and younger people. If stepping on the scale makes you feel worse, weigh once a week or put it away for a while, and track your waist and photos instead. If you’ve ever had an eating disorder, talk with your doctor before you start.

Want to see what real change can look like? Read these before and after stories.

Frequently asked questions

Sources

• NHLBI (NIH): Assessing your weight and health risk (how to measure your waist; 35 and 40 inch thresholds)
• CDC: Losing weight (1 to 2 pounds a week; talk with your health care provider)
• Withings: Body Comp, frequently asked questions about safety (pacemakers, implants, pregnancy)
• NIH Technology Assessment Conference: Bioelectrical impedance analysis in body composition measurement (Am J Clin Nutr, 1996)
• Bosy-Westphal et al.: Accuracy of bioelectrical impedance consumer devices compared with DXA (Obes Facts, 2008)
• Orsama et al.: Weight rhythms, weekly weight changes (Obes Facts, 2014)
• Madigan et al.: Self-weighing in weight management, a systematic review and meta-analysis (2015)
• Steinberg et al.: Daily self-weighing and adverse psychological outcomes, a randomized trial (Am J Prev Med, 2014)
• Pacanowski et al.: Self-weighing, throw out your scales? (review, 2015)
• Fuller et al.: Reliability and validity of commercially available wearable devices, a systematic review (2020)
• CDC: About BMI (BMI does not distinguish between fat, muscle and bone)
• Shcherbina et al.: Accuracy in wrist-worn sensor-based measurements of heart rate and energy expenditure (J Pers Med, 2017)
• TechLiving: The best smart watches for fitness tracking (five picks, if you want a watch instead of a band)
• Saint-Maurice et al.: Daily step count and mortality among US adults (JAMA, 2020)
• Block et al.: Consumers’ estimation of calorie content at fast food restaurants (BMJ, 2013)