Dear Lucy: Your answer to the question about basal metabolic rate just raises another question in my mind: Let’s say, just hypothetically, that a woman has been consuming fewer calories than her “total daily energy expenditure,” or TDEE, and still is not losing weight. What should she do? Talk about frustrating! —T-weedle-DEE
Dear T-weedle-DEE: The situation you describe certainly does sound frustrating! Hypothetically speaking, of course. For an answer to your question, Lucy returned to our resident calorie guru and source for the previous answer, MIT Medical Nutritionist Anna Jasonides.
As Lucy suspected, Jasonides was quickly able to formulate several hypothetical explanations for your hypothetical conundrum:
- Underestimating calories consumed: According to Jasonides, many research studies have shown that actual caloric intake is often much higher than people’s best estimates. The most likely culprit? Miscalculating portion size — a problem any time, but especially, Jasonides says, when eating out. Need some help? Here’s a printable, wallet-sized guide you may find helpful.
- Overestimating calories burned: At the same time that people are underestimating their caloric intake, Jasonides says, they tend to overestimate the number of calories they are burning through exercise. “Unfortunately, walking for a half hour three times a week — while good for overall health — barely makes a dent when it comes to weight loss,” she says. “Experts recommend that people who want to lose weight to aim for 60–90 minutes of moderate activity every day.”
- Calculations don’t work as well at the extremes: “The equations in my previous answer yield the best estimates for people who are close to their ideal weight,” Jasonides clarifies. “If you’re obese, the TDEE calculation is likely to overestimate your daily caloric expenditure; if you are very thin, the result will probably be an underestimate.” For individuals on these two weight extremes, Jasonides suggests redoing the calculation using ideal body weight rather than actual weight.
- Everyone is different! Finally, Jasonides acknowledges, your hypothetical woman could be doing everything correctly but still have trouble losing weight because her individual metabolism is slower than average. “Equations for estimating basal metabolic rate and caloric burn are based on averages,” Jasonides says. “You may have a different ‘set point,’ which means your body will resist weight loss even when the math says you’re operating at a caloric deficit.”
It’s possible to obtain a direct measurement of metabolic rate by measuring oxygen consumption through a quick, non-invasive test. Though this is not a procedure we can perform at MIT Medical, this test can be done at another outpatient facility and can be helpful in determining an individual’s optimal caloric budget for weight loss or maintenance.
Jasonides adds that there are also several medical conditions that may hinder efforts to lose weight, including insulin resistance and hypothyroidism. In any case, she suggests — and Lucy agrees — that anyone who is having trouble losing weight should start by consulting a nutritionist for an assessment and, perhaps, a reality check. “A nutritionist can help you figure out if your calculations of caloric intake and expenditure are correct and can offer additional information and suggestions to help you reach your weight-loss goals.” Jasonides says.
Lucy hopes her answer to this hypothetical question will be helpful to all the very real people out there who are trying their best to reach a healthier weight. —Lucy