How Fitness Trackers Sabotage Weight Loss

Lots of people use diet and activity trackers to log their food intake and exercise. After all, there’s an old saying that “you can’t manage what you don’t measure.” And yet it seems to be backfiring.

I get email after email from people using these trackers who can’t understand why they’re not losing weight. They’re entering in every morsel of food and logging every activity. According to their trackers, they should be shedding two or three pounds a week. And yet the scale hasn’t budged—or they’ve actually gained weight!

This article is also available as a podcast. Click to listen

The problem with net calories

Here’s how many of these trackers work: You start every day with a certain number of calories to spend. That number is based on your height, weight, age, sex, activity level, and your goals—that is, whether you’re trying to lose, gain, or maintain your current weight.

Calories are subtracted from your balance as you log your meals into the diet tracker over the course of the day. Ideally, you don’t get to zero too early in the day. But if you do, there’s a solution. Let’s say it’s 5 pm and I’m down to my last 400 calories. But wait! I can take an evening run, log it into the app and now I’ve got 840 calories to spend on dinner! How awesome is that?

The general principle here is sound: The more you move, the more you can eat. In practice, however, these “net calorie” calculations are inaccurate and misleading—and they are suckering people into eating too many calories. Let me explain.

How logging exercise leads you astray

Although diet tracking apps can help you get an accurate picture of your calorie intake, they are much less reliable in determining how many calories you burn. Here are at three ways they tend to get it wrong.

Mistake #1: Your baseline may be too high.  In order to calculate your baseline calorie requirements, you indicate your activity level: sedentary, lightly active, moderately active, or very active. This does not refer to how much you exercise (we’ll get to that in a moment). This is just about your daily activity level. And guess what? Most people select an activity level that’s one or two categories higher than their lifestyle actually warrants. Unless you rope cattle eight hours a day, your lifestyle probably does not qualify as “very active.”

If you use a wearable fitness tracker like a Fitbit or Apple Watch or even a low-tech pedometer or step counter, you can use that to help you select the proper category for your lifestyle. Here’s an easy cheat sheet:

  • Fewer than 1,000 steps a day is Sedentary.
  • Fewer than 10,000 steps or about four miles a day is Lightly Active.
  • Ten to 23,000 steps or four to 10 miles a day is considered Active.
  • More than 23,000 steps or 10 miles a day is Highly Active.

If you walk or run for exercise, you can count those steps and/or miles toward your baseline activity level if you want, but then you can’t enter them again as exercise. They’ve already been counted.

Mistake #2: The calories burned from additional activity are often overestimated.  Most diet tracking apps give you a place to manually log physical activities and exercise, such as a spinning class or yard work or ballroom dancing. Alternatively, there are wearable devices that sense your movement and changes in your heart rate.  Either way, you may not be burning anywhere near as many calories as your app thinks. As with the readouts on the aerobic equipment at your gym, diet and fitness trackers may overestimate calories burned by anywhere from 10% to 25%.

For one thing, the more you do a given exercise, the more efficient your body becomes at performing that motion. As a result, you burn fewer calories. The first time I run an eight-minute mile, I’m probably going to burn more calories than the 100th time I run an eight-minute mile.

Not only that, but when we burn a bunch of calories exercising, our body actually adjusts by burning fewer calories the rest of the day.  A new study finds that the body of a reasonably fit person may “recover” up to 28% of the calories burned through exercise by burning fewer calories at rest.  Ironically, the more fat tissue you have, the greater this effect.  As researcher John Speakman explains,

“When your smart watch tells you that you burned 300 calories on your run it may be correct (probably isn’t). But even if it is correct, you should not be deluded into thinking you can now eat 300 calories more food.”

Mistake #3: You may be counting some of those calories  twice.  If I spend the next hour sitting at my computer writing this podcast episode, I’ll burn about 100 calories. Those non-active calories are already accounted for in my daily calorie allowance. If I spent the next hour on the stationary bike instead, I’d burn 500 calories. That’s 400 more calories than I would have burned writing this episode. But if I log my bike ride into my diet tracker, it doesn’t add 400 calories to my total allowance … it adds 500. Essentially, it counts those 100 baseline calories twice.

The more activities you enter in to your exercise diary, the more this double-dipping error compounds—especially if you’re logging a lot of low-intensity activities like housecleaning or yoga.

I recently heard from a Nutrition Diva listener who said she burned 3,000 calories a day. She was only eating 2,500. She couldn’t figure out why she was gaining weight.  Sure enough, she was using an app to track her food intake and exercise.

According to her app, her baseline calorie needs were about 1,800 calories a day. She then logged activities for almost every hour of her day: making beds, folding laundry, unloading the dishwasher, yoga class, walking the dog, grocery shopping, car-pool, weeding the garden, playing the piano, cooking dinner, folding laundry, and so on. According to her tracker, all those activities were burning an extra 1,200 calories a day—which gave her a total “net calorie” allowance of 3,000 calories a day. She figured she could eat 2,500 calories a day and still lose weight.

In reality, all of her routine activities probably only burned a couple hundred calories above and beyond her baseline. Instead of eating 500 calories less than she burned each day, she was really eating 500 calories more than she burned each day. No wonder she wasn’t losing weight!

How to avoid the net calorie trap

Activity trackers are a great way to keep track of how active you are, but they aren’t very accurate at estimating your calorie expenditure. Adding “calories burned” to your daily calorie allowance can result in unintended weight gain.  So, I’d suggest that you don’t log your exercise and other activities into your diet tracker or sync your wearable fitness tracker to your diet log. Even better, I’d encourage you to stop thinking of exercise as simply way to burn calories or earn food and focus on the many other benefits it provides instead.

See also: What if exercise burned zero calories?


  1. Careau, Halsey, et al.. Energy compensation and adiposity in humans. 2021.


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Nutrition comparison of gluten-free flours

In this week’s episode of the Nutrition Diva podcast, I reviewed the nutritional benefits of watermelon seed flour in comparison to other gluten- and grain-free flours. You can listen to the episode here and below is a chart showing the nutritional values for several of the most common types.

1/4 cupCaloriesProtein (g)Fat (g)Sat fat (g)Carb (g)Fiber (g)Calcium (mg)Potassium (mg)
Watermelon seed flour17891535017207
Almond flour16061206472210
Coconut flour12063218106600
Cassava flour13000031220106
Gluten-free baking flour130200301459
Paleo baking flour110440.513327160
White pastry flour12030.50261658
Whole wheat pastry flour11040.502337111

What’s the healthiest way to eat rice?

In this episode of the Nutrition Diva podcast, I break down the differences between all the different types of rice. Which are most nutritious? Easiest on your blood sugar?

Nutritional comparison of rice varieties

1/2 cup, cookedCalories (kcal)Protein (g)Fat (g)Carbs (g)Fiber (g)Mg (%DV)
White, long grain1052022<12.4%
White, short grain1352029<12.1%
White, converted95202111.8%
Basmati (white)902021<12.4%
Jasmine (white)1052022<12.4%
Brown, long grain12531261.59.8%
Brown, medium grain1102123210.7%
Brown, converted11521241.37.6%
Black rice11531231~
Red rice11021232~
Wild rice8530181.56.5%
Glutinous (sticky) rice852018<11%

How do pili nuts compare nutritionally?

This week’s Nutrition Diva podcast is all about the pili nut, the latest entry into the superfood derby.  Below is a chart showing how they stack up to other nuts nutritionally.

1 oz/30 g provides:Pili nutsAlmondsWalnutPeanutCashewMacadamiaCoconut
Fat22 g14 g18 g14 g12.5 g21.5 g9.5 g
Saturated10 g1 g2 g2 g2 g3 g8.5 g
Monounsat.10 g9 g2.5 g7 g7 g17 g1.4 g
Omega 3----2.5 mg-- ------
Protein3 g6 g4 g7.5 g5 g2 g1 g
Fiber1 g3.5 g2 g2.5 g1 g2 g2.5 g
Vitamin E10 mg7 mg02 mg-----
Calcium40 mg76 mg28 mg26 mg10 mg24 mg4 mg
Magnesium85 mg76 mg45 mg48 mg83 mg37 mg9 mg

Is protein powder too processed to be healthy?

Catherine writes:

“Virtually everyone says to cut down on processed foods.  It’s  one of the few things everyone from different camps generally agrees on.  Yet a large number of nutrition “influencers” recommend smoothies that include protein pea powder, or “beef powder”.  How the heck are those not processed food?”

You’re right: Pea protein and beef powder (yuck) would both be considered processed foods. As would soy or almond milk, yogurt, or frozen strawberries.

Virtually everything we eat is processed to some degree. Perhaps it’s helpful more to think of processing on a spectrum.  A grape still on the vine would be at one end and a grape-flavored jelly bean on the other. Somewhere in between those extremes would be raisins, grape juice, and grape jelly.

The goal is not to completely eliminate processed foods (which wouldn’t even be possible).  It’s more realistic to think about choosing foods that are closer to the less processed end of the spectrum as often as we can.

What’s the purpose of the processing?

Rather than painting all processed foods with the same brush, it’s also worth considering what the purpose of the processing is.  Is it to concentrate the sugar, increase the intensity of the flavor, or otherwise create a product that hyper-stimulates the reward centers of the brain?  Is it to increase the profit margin of a cheap ingredient?

Or does it serve to extend shelf life, increase the nutritional value of a food, improve its digestibility, or make a nutritious food safer or more convenient to prepare?

Obviously, the processing required to turn peas or whey into protein powder serves a different purpose than the processing required to turn an ear of corn into a bag of Cool Ranch Doritos.

If you enjoy smoothies, you can consider whether the benefit of the additional protein justifies the use of a somewhat processed ingredient like protein powder.  Your answer might depend on how easy it is for you to meet your protein needs from other foods in your diet.

Either way, though, even though it is somewhat processed, a smoothie would be closer to the less processed end of the spectrum than a strawberry-flavored McFrosty.

My diet is super healthy. Why isn’t my Nutrition GPA higher?

I received the following email from a frustrated user of the Nutrition GPA app.  I’m posting it here, along with my response, in case other app users might find it useful as well.

“I have been somewhat frustrated with the scores I’ve been getting on the Nutrition GPA app.  I know I definitely do not eat enough fresh fruits and vegetables some days. But I think my diet is very good otherwise–just not in ways the app measures!

“For instance, I don’t eat any meat, I eat no dairy on an average day, I rarely eat eggs, I obsess over sodium, I rarely eat baked goods–and when I do, they’re homemade, low sugar, low sodium, dairy-free, etc., and the only white flour I eat is in baguettes, Portuguese rolls, or occasional pasta. Nevertheless, I’m getting Cs and  even a D!”

How does the Nutrition GPA assess your diet?

The questions in the Nutrition GPA quiz represent the foods most strongly associated with overall diet quality, risk factors, and health outcomes.  If your grade is not as high as you think it should be, perhaps aspects of your diet that you think are “not so bad” or “occasional” are having more of an impact than you realize.
Conversely, aspects of your diet that you think of as  “very good” may not have as much impact (or be as consistent) as you think.
Let’s take a closer look at some of the details you mentioned:
  • If you don’t eat any meat, then you are always getting points on Q9.  So that’s certainly not responsible for your low grade!
  • Avoiding diary and eggs is not associated with improved diet quality or reduced health risks.  So they don’t impact your grade one way or the other.
  • If you have high blood pressure and are sensitive to the effects of sodium, then that might be an important thing for you to watch. But for the majority of the population, avoiding sodium does not improve their health or their risks. So it’s not monitored in the Nutrition GPA.
  • Baked goods that contain white flour will impact your grade–even when they are homemade, low sugar, low sodium, and dairy-free! If you’re only eating them occasionally, it shouldn’t affect your GPA too much.  But research shows that replacing white flour with whole grain flour (or avoiding it altogether) improves health and nutrition.  And that’s why you get a higher grade on days when you don’t eat things made with white flour.

There are also a few things that you DIDN’T mention. But if you are frequently having more than one alcoholic drink, more than 25 grams of added sugar, eating fried foods and/or you rarely eat fish, legumes, and nuts, this will drag down your Nutrition GPA.

All of which is to say that the whole point of the Nutrition GPA is to shine a light on those areas of our diet that could stand improving. And sometimes it reveals things that we may have over or under-estimated.  In which case, it’s working exactly as designed–and presents a great opportunity to improve your nutrition!


How sleep affects weight gain with Dr. Jade Wu

Many people have more difficulty sleeping when they reach midlife, which is also when they start to see their weight creeping up. In this episode of the Nutrition Diva podcast, sleep medicine specialist Dr. Jade Wu talks about the relationship between sleep, appetite, weight gain, and midlife changes.

Highlights from our conversation

Monica Reinagel: I’ve written a lot about the connection between sleep and hunger, appetite, and weight management. But I’m looking at this problem as a nutritionist. How do you see the relationship between sleep, appetite, and weight management as a sleep expert?Jade Wu:  When we are sleep deprived, the body compensates for lack of energy by craving more calories and tends to reach out for more saturated fats, carbs, and sweets. We also have less leptin and more ghrelin levels in our blood after a night of not enough sleep, which is how these hormones behave when we’re very hungry.

What’s less talked about is the role that our circadian clocks play in all of this. We all have biological clocks that follow a roughly 24-hour rhythm, and these clocks love to run on time. Having a disrupted circadian rhythm (jet lag, shift work) can slow down our metabolism, make us crave more high-fat foods, and generally increase the stress on our bodies.

Psychologically, this stress from a disrupted body clock (together with the stress of insufficient sleep) makes us less motivated to stick to healthful behaviors… it makes us more cranky so we’re more likely to eat as a way of regulating our emotions… it makes us less energetic and less likely to be active.

So there are both biological and psychological ways that insufficient sleep and a disrupted circadian rhythm can affect weight loss and nutrition.

MR: Most of us the basics of good sleep hygiene (avoiding screens, caffeine, alcohol, keeping a consistent schedule, cool, dark rooms, etc.). But a lot of people still struggle to sleep through the night, despite taking all of those steps. You’ve suggested that sleep hygiene may not be all that. So what is the solution?

JW: Sleep hygiene is a good place to start. It’s like dental hygiene… good as a general baseline, but not enough if you already have a cavity.

If you do have a sleep disorder, like insomnia or sleep apnea, it’s important to get those addressed using evidence-based treatments. Like you mentioned, sleep hygiene is the placebo condition in our clinical trials… not enough to cure insomnia. What is recommended by the American Academy of Sleep Medicine as a first-line treatment is cognitive behavioral therapy for insomnia (CBT-I).

MR: A lot of people develop sleep issues for the first time as they get into midlife–which is also when many of them start to see their weight creeping up. First, Is there something physiological that occurs in midlife that affects sleep rhythms? Or have we just had longer to develop bad habits? Or more to worry about?

JW: There are physical and psychological changes. In terms of physical changes:

  • We need less sleep as we age
  • Our sleep tends to be more often punctuated by wakefulness, and we tend to have less deep sleep
  • Hormonal changes like menopause can certainly disrupt sleep… but this should not permanently make you a bad sleeper
  • More aches and pains, less physically and socially active

As for psychological changes, our expectations need to move along with the physical changes.

  • We may get more anxious about sleep and health
  • We may become increasingly psychologically dependent on sleep aids
  • We’ve had longer to learn unhelpful things… like our brains learning that the bed is an awake place

MR: In your opinion, then, how much of an impact does midlife sleep difficulty have on midlife weight gain?

JW: This is hard to tease out because there are so many things that are changing mid-life… perhaps our activity levels, our social lives, our stress levels, our eating habits. I see this time as an opportunity to tune up health in all domains, such as learning to cook more nutritious meals now that the kids have left the house and you have more time. Or doing more self-care, taking up meditation… all good things for sleep and overall health. There’s no reason why sleep has to be bad in midlife or after.  It will change, but if you listen to your body and change with it, you can still have great sleep health.

Recommended Sleep Resources

Penn CBT-I Provider Directory

American Academy of Sleep Medicine

This article originally published at

Lose More Fat and Less Muscle with Slow Weight Loss

A new paper in the British Journal of Nutrition asks whether the pace at which you lose weight affects how much of that lost weight is fat (as opposed to muscle) and the impact on your metabolism after weight loss. To answer this question, the authors pooled the results of seven studies that compared rapid to gradual weight loss, where both groups lost about the same amount of weight but at different speeds.

This is a question that I am very interested in, so I was excited to find a breakdown of this new study in a recent issue of the Nutrition Examination Research Digest, a terrific publication affectionately known to subscribers as NERD.

This article also available as a podcast. Click to listen.

Advantages of slower weight loss

For years, I’ve been advocating slow weight loss as a better way to achieve sustainable weight loss, which is the only kind that really counts and the hardest to achieve.

Make smaller but more permanent changes to your habits and behavior. The weight comes off more slowly, but you aren’t just losing weight; you’re learning how to be someone who weighs less.

Part of my rationale for this approach is psychological and behavioral. To lose weight quickly, diets usually involve a dramatic but temporary change in your behavior. Once you’ve lost the weight, however, you tend to revert to old habits and behaviors that lead you to regain the weight you’ve lost.

Instead, I’d rather see you make smaller but more permanent changes to your habits and behavior. The weight comes off more slowly, but you aren’t just losing weight; you’re learning how to be someone who weighs less.

But another big part of my rationale is physiological. Many popular diets are designed to produce weight loss at a rate of 5-10% of your body weight per month. But that’s significantly faster than most people can shed body fat. If you’re losing weight faster than you can lose fat, that means you’re losing lean muscle, and that’s not what you want to be losing.

RELATED: How Fast Can You Lose Fat?

I’m convinced that slower weight loss (2% or less of your body weight per month) results in losing more body fat (and less muscle). It’s also less likely to cause a slowdown in your metabolism, which is going to make it easier to maintain the weight loss. And I’m always on the lookout for research to either support or refute this belief.

To date, there have only been a handful of studies on the advantages of slower weight loss, some of them pretty small. The latest attempts to get a better grasp on the subject by pooling the results of several studies and doing a meta-analysis of the results.

What research says about slower weight loss

Joining me to talk about the results is Gregory Lopez. He’s editor in chief of the Nutrition Examination Research Digest and He obtained his master’s degree in molecular biophysics from Johns Hopkins University, and his doctor of pharmacy degree from the University of Maryland, Baltimore. Greg and his team took a closer at this study in a recent issue of the Nutrition Examination Research Digest

Greg, first give us the topline: How did slow weight loss compare with fast weight loss in this meta-analysis?

Overall, their conclusion is that slow weight loss is better for body composition than fast weight loss. There are a couple of caveats based on their selection criteria. They looked at studies that had similar total amounts of weight that were lost. And so these results would not apply to people who lose more weight on one program versus another. Also, the studies were relatively short term—all less than a year.

They also looked at the resting metabolic rate. We know that when we restrict calories, eventually the body may adjust its metabolic rate downward in order to conserve energy. And that’s, of course, the bane of dieters everywhere. If we’re restricting calories more dramatically in order to lose weight more quickly,  is that having an even more deleterious effect on resting metabolic rate? What did they see in terms of resting metabolism?

The metabolic rate didn’t sink as much on a slow diet as opposed to a fast diet. Essentially, slower dieting came out on top.

Whenever we have studies comparing fast versus slow weight loss, my question is always: How fast is fast and how slow is slow? And when you and I went through the individual seven studies that they looked at, we found a really big range. The slow paces ranged from less than half a pound a week, which is pretty slow, to over two pounds a week. The fast paces ranged anywhere from one to four pounds a week.

There were a couple of studies where the slow pace was actually faster than the fast pace of one of the other studies! How does that impact what we can take away from these results?

It does muddle things. You really can’t answer the question of how much going slower or faster changes things given the analysis they did here and the data that’s available. It would have been really interesting to see an individual-level meta-analysis.

A meta-analysis takes a bunch of studies and lumps them together, and it takes the average results of these studies. So you’re taking an average of an average. If you can get the data for each individual person in the studies, you can pull them all into one single big study. And since you’d know how much exactly each person lost, rather than how much they lost on average within a study, you can do a dose-response analysis. So, if you’re interested in figuring out how slow is slow enough and how fast is too fast, that kind of analysis could be useful.

So, what we know from this particular meta-analysis is that  it looks like whether you’re losing weight faster or slower does make a difference in terms of how much fat you lose. What we can’t answer from this study is: What is the sweet spot? What is the perfect pace where most of the weight you’re losing is fat and the least is lean muscle. That is still an open question. 

I would agree with that. And I would also say that it provides a direction for future research.

I also want to talk a little bit more about the Nutrition Examination Research Digest. Tell us a little bit about what you do at

We try to distill the research around nutrition and supplementation—what the evidence says works and what doesn’t work. And we pride ourselves on being independent. Our goal is to kind of help people who are nutrition enthusiasts, or even professionals, get some of the latest evidence that they need.

I think you guys do such a great job—not only at going through the research but putting it into context, explaining some of the trickier concepts and pointing out potential weaknesses. I also think it’s extraordinary that you do not sell any products and don’t accept advertising. This work is completely supported by your subscription fees. That puts it pretty much in a class by itself. So, thank you for what you do, Greg, and for joining me today to add your insights. 

Digging into the Data

After my conversation with Greg, I did delve into the details of a couple of the larger studies included in the meta-analysis, where the slow pace of weight loss matched what I would recommend, to see how those folks fared.

Although both groups lost the same amount of weight, the slow group lost 10% more body fat than the faster group and 50% less lean muscle.

One of them involved 200 subjects, both men and women. Over the course of the study, the subjects lost 15% of their starting body weight on average. The slower group lost at a pace of about 1.5% of their total body weight per month. The faster group lost at a more typical rate of 4.5% of their total body weight per month. Although both groups lost the same amount of weight, the slow group lost 10% more body fat than the faster group and 50% less lean muscle.

The other study I looked at involved 68 subjects, all men. This was a shorter study and so the total amount of weight lost was less: about 6% of their starting body weight. But the pacing was virtually identical. The slower group lost 1.5% of their total body weight per month and the faster group 4.5% per month. But the difference in body composition was a lot more dramatic. The slower group lost 50% more fat and 75% less lean muscle than the faster group.

In short, slowing down the pace of weight loss does appear to offer some real advantages. For more on my approach to creating sustainable weight loss, please check out the resources at Weighless.Life.

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