Using activity levels to determine calorie burn/intake

[JMillerfdu]

I currently use Lifesum app to log my nutrition. My BMR is 1,654. I use lightly active because I’m mostly somewhat active. Stand on my feet for eight hours during work. I also go to the gym 4/5 times a week. I believe calculated the TDEE comes out to about 2,200, but is that only with activities like walking and shopping and etc, or is that also with workouts at the gym? Does the Fitbit versa 3 make it easier to calculate how many calories you burn instead of guessing whether I’m hitting that deficit? Currently I’m trying to eat 1900/20000 calories and consider that workouts would be extra calories burn or should I consider it apart of my activity.

[Heybales · Accepted solution]

If Lifesum is like most sites with a TDEE calc, they are using the same tired formula from a 1919 study by Harris, which also created the Harris BMR estimate that has been improved on many times.

That calc only takes into account workouts - 1-3 hrs weekly, 3-5 hrs, right?

No description of daily activity level differences is there?

So your guess of Lightly-Active (which is 1.375 x BMR probably) is not correct for both daily and workouts combined.

So those calcs will have say 2 men equal physical stats and doing say 3 hrs of lifting a week, but one a mail carrier with 4 kids nights/weekends, and other a single programmer/gamer most nights - with equal TDEE.

Absurd.

Also - 5 hrs of intense cardio vs 3 hrs of lifting weekly is assumed to be the same amount of burn according to what it's doing.

Absurd.

Your device is on you, and while the Fitbit also is making some bad estimates - it's on you. Can learn an adjustment or tweaks to that.

Daily steps, actually distance, with weight moved is very accurate calc of calories burned.

Sadly standing with no steps is still given BMR sleeping rate of calorie burn - so underestimated there.

During exercise the HR-based devices will now use a HR-based calorie calculation - which is only valid for steady-state aerobic exercise - not intervals and anaerobic like lifting.

But even if it's 100% inflated during that time of incorrect usage - how much time weekly is it? 3 x 20 min? or 6 x 90 min?

One matters, the other is a blip.

Weights is better to manually log from database though, overwrite what Fitbit came up with using HR. It's not nearly the same amount of calorie burn - but that is true for lifting.

Interval stuff like the mis-named faddish HIIT workouts (they aren't true HIIT) are usually not that long, unless you have progress to 90 min sessions many days a week - then manually logging as calisthenics would be better.

In either case - start the workout on the device so you have a time stamp, and HR info for review later, it is interesting.

But then create a workout which will overwrite the calorie burn with a better estimate.

Now you have a better idea of daily burn.

Now you remove a deficit to cause hopefully just fat loss (keep it reasonable, extreme diets lose more than fat and stress body - not good).

Now you have an eating goal based on what you actually did.

And yes it can make it easier to know you are hitting a deficit, and allow you to fuel your workouts to recover better, and have better ones.

After all, why would you spend the energy and time doing the workouts if not to get benefits from them beyond mere calorie burn.

Those workouts are what's going to transform the body so when the fat is gone there is something there besides more fat. "skinny-fat" is term.

And heart health!

So it is for sure a part of your activity - many of the calories you eat are going right off to power those workouts. Don't count them and what's going to be left to aid repair, and normal body functions?

[Glenda]

@Heybales  You give people GREAT answers.  I wonder if it might be more simple and easier to understand though, if you just asked, "What is the goal?"  Exercise is for health and body building, it usually doesn't help at all in losing weight.  Studies show the people who begin an exercise program to lose weight eat more and DON'T lose weight.  I use almost as many calories sitting in a chair all day as when I walk 7,500 steps.  My heart and body temperature use lots of calories no matter what I'm doing.  

[Heybales]

I think you'll find every study that shows exercise has no positive effect on weight loss is when people are left to still eat as they desire. Free-form studies. Those are used with Keto and Intermittent fasting and other diet types sometimes, along with exercise or non, just to see if the diet or exercise all on it's own can have a positive effect for weight loss. Sadly people can overeat no matter what is used if they do NOT account for calories IN and calories OUT (CICO).

I'd love to see a study where they equated calorie deficit, meaning the people had to eat a certain amount - and exercise had no effect.

I've seen all studies so far to show exactly that - if people log their foods accurately and account for daily burn correctly (which includes ALL daily activity) then they do lose weight. When those are measured on both sides in a study setting - the loss is as expected.

I'm just concerned about the general guidance thrown out to all coming with questions.

I can guarantee you don't burn almost as many daily calories between sitting in chair and walking 7500 steps. The shorter, the lighter, the older someone is then of course the difference isn't going to be as great. But not everyone is on the extreme side of the ranges. Those on the other side of the ranges (taller and heavier and younger) will show a much greater difference between those 2 states.

Even a device like Fitbit which is NOT measuring calorie burn and could be fooled and give low estimate to the walking - will still show the fact there is a difference.

Please check a hospital around you that does VO2 max tests (many heart focused places do) and just get an Indirect calorimetry test of you sitting there for 5 min, and then walking several speeds up to whatever you care to test to. You'll be shocked. And then remember where you fall in the scale of averages and how much more others will burn doing the same test.

Because people are starting a new year - there will be a ton of people going nuts on the exercise activity (meaning well above sustainable in their life) - and to say exercise doesn't count for calories and eat as if not doing it - will just cause some bad problems not merely for sucky workouts - but too big a deficit caused by undereating too much does have negative effects on a body and success at losing just fat weight.

Remember your personal study of n+1 only has results that apply to you, they don't have blanket application to everyone else.

Here's a different personal study of n+1 and her results.

https://skepchick.org/2014/02/the-female-athlete-triad-not-as-fun-as-it-sounds/

And here's an actual study of negative effects of too great undereating.

Martin CK, Heilbronn LK, de Jonge L, Delany JP, Volaufova J, Anton SD, Redman LM, Smith SR, Ravussin E. "Effect of calorie restriction on resting metabolic rate and spontaneous physical activity", Obesity (Silver Spring). 2007 Dec;15(12):2964-73. PMID: 18198305 http://www.plosone.org/article/info:doi/10.1371/journal.pone.0004377