calorie needs and deficit confusion, can I get some help please?

[Fuzion_Reaktor]

To put things simply I've been all over the internet looking for calorie needs and deficit calculators and I've gotten weird answers. I'm a 5'11.4" 21 year old guy weighing 246lbs at 31% body fat (hence I'm here and have bought a fitbit) and I'm just wondering what I should be aiming for in terms of calorie intake.

Also, is a 2000 calorie daily deficit too much? Some calculators say I should aim for ~2000 calorie intake and if that's so I can fairly easily burn 4000 calories a day according to my (calibrated) fitbit.

Thanks 🙂

[Fuzion_Reaktor]

forgot to say I exercise on the treadmill daily. If that affects how many calories I'd need.

[FitBeforeFifty]

First, calculate your BMR:

http://www.bmi-calculator.net/bmr-calculator/#result

This is how many calories you would burn if you laid in bed all day long.

Based on your stats, that's 2357. Most people will suggest that you not eat below this amount because that's how many calories your body needs to just perform basic functions.

Your TDEE (total daily energy expenditure) is your BMR + ActivityCalories. If your TDEE is 4000 calories, as you suggest, and you ate at your BMR that would leave you with a deficit of 1643 calories. You will lose about 1 lb per week if you maintain a 500 calorie deficit per day. At 1643, you would lose 3.2 lbs per week.

Keep in mind that as you lose weight your TDEE will drop as well, so you'll have to reduce your calorie intake to sustain that rate of weight loss. Essentially you have to keep recalculating your BMR as you lose weight. Fitbit should adjust your BMR/TDEE calculations automatically if you continually update your weight.

In my opinion, that's under eating and could lead to burn out pretty quickly. In the beginning, it might not seem too bad, but after weeks and months it could lead to binging and/or giving up. Personally, I think the best choice is too pick an aggressive deficit early in the process and then reduce the deficit over time so that you actually might be eating a little more over time instead of having to eat less and less.

In other words, maybe start out eating at your BMR for a couple weeks. Then increase your calorie intake so maybe you are losing at 2 lbs per week. After a month or two adjust it to 1.5 lbs per week. A month or two later adjust it to 1 lb per week etc... This gives an increasing calorie budget as time passes instead of a death spiral calorie intake that just keeps getting lower and lower.

[Dominique]

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@Fuzion_Reaktor wrote:

I can fairly easily burn 4000 calories a day according to my (calibrated) fitbit.

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Be careful with the calories you burn according to your Fitbit: even if it’s "calibrated" (whatever you mean by that), there’s a relatively large margin of error.

I used this online calculator (which use more or less the same formula as Fitbit, Mifflin-St Jeor) to see what activity level you would need (given your age, weight and height) in order to burn about 4000 calories per day: it’s the highest possible level ("Extreme Activity").

I had a look at your profile:

You seem to average about 6000 steps per day. In my experience, this wouldn’t put your activity level in the highest class ("Extreme activity, Very Hard Exercise 6-7 Days/Week"). For that, you would probably need something closer to 20,000 steps per day in average. Now, your activities may include a lot of non-step-based stuff which your Fitbit wouldn’t pick up (or pick up fully), but 6000 daily steps is more like "Light Activity", just above sedentary.

If your Fitbit tells you you burn 4000 in average, I would eat 3000 for a couple of weeks, then look what happened to your weight. Theoretically, you should lose 4 pounds during that time (cumulative deficit = 1000 x 14 = 14,000 calories, 1 pound = 3500 calories => 14,000 calories = 4 pounds). If it’s not the case (weight loss smaller than 4 pounds), either your Fitbit overestimated calories burned, or you underestimated your intake, or both. You may have to empirically find the right balance of exercise and eating in order to achieve the actual deficit you need.

[FitBeforeFifty]

@Dominique makes a very good point regarding calorie burn.

I'm new to using a fitbit but I've been tracking my calorie intake and calorie burns for 5 years using another app (I use the loseit app). Since I've maintained my goal weight for 4 years I feel pretty comfortable with how I previously calculated my TDEE.

I've been using the Charge HR for 3 weeks now and while I love it overall, the calorie burns are quite a bit higher than what I'm used to. On average, I would say about 500 calories per day higher than the numbers I've previously used. For real exercise, it seems to do a pretty good job. It gives me about 541 calories for a 5 mile run, my previous app gave me 492. On the other hand, I get 199 calories for 30 minutes of table tennis -- which I find pretty generous. It also gives me quite a few calories for my normal daily activities which seem very generous. I've gotten a fitbit adjustment (calories over sedentary) on a saturday when I literally did nothing but sit around the house all day.

So, like @Dominique said, you'll have to experiment to find what number you believe in terms of TDEE calculation. My only suggestion is to not decide prematurely. You need several weeks of consistent tracking to get any kind of statistically relevant number.

[Fuzion_Reaktor]

OK what you have viewed of my profile isn't very representative of me. I spent pretty much all f April sitting and studying for Finals and then hurt myself not long afterwards. But also I was one of the people who had syncing issues with my fitbit since about december and I'm prett sure my profile is nowhere near accurate or might not evenhave any data until April. if it does is it probably wrong. Anyway 4000 is what I could get my fitbit to say if I tried fairly hard I am usually doing more like 3500 to 3700 calories a day.

And by calibrated I mean I have gotten my stride length down right and switched the dominant hand setting because it used to overcount my steps too much and it is now pretty much accurate. I've also tested by heart rate during exercise with some other tools and found my firbit was very close.

[Fuzion_Reaktor]

HI FitBeforeFifty

I had gotten the feeling that my fitbit is overestimating too but from about five different online calculators I've checked my charge hr is almost dead on with what they give. Most say I will burn 3000 to 3200 calories while being sedentary and 3500+ with light activity.

I have no idea what my profile will say about my calorie burn for the past few months since I had a lot of syncing issues since december, a coupld of failed resets, and two months of midterms and finals. But when I said I can burn 4000 calories fairly easily I meant that is what I can get my fitbit to say with extra exercise on top of my normal.

And by calibrated I meant I had fudged with settings so that my fitbit is counting my steps very accurately now. It used to overcount. and it is almost always dead on with my heart rate.

[Ukase]

If you're cooking off 4000 calories a day, you should be able to drop weight just by using a 1000-1500 caloric deficit. 

The problem is - despite your height, weight and age, I've no idea if you're done growing. Probably not. Studies have suggested that our brains keep developing into the mid-20's. So, you have to take it easy on a huge caloric deficit. 

I would go with the tried and true method of a 1000 caloric deficit a day. Take in 3000 calories a day for a week - and if you've lost 2 pounds that week, just keep on doing that until your weight loss effort stalls. 

Then, reduce your caloric intake to 2500 calories a day until it stalls. Shouldn't take you too long before you're where you want to be. 

Most importantly - realize that your fat cells are not going away - they're just shrinking in size. Every time you overeat and gain fat, it will be that much harder to lose the weight next time. Because when you overeat - the fat cells you already have don't get bigger, you get new ones, too. That's why yo-yo dieting is no good. Whatever actions you take to lose the weight - realize that you have to maintain those actions or the weight will creep back on. 

[Fuzion_Reaktor]

I get the growing thing and know I shouldn't dip too low. I'm just mostly confused about what too low is for me. Also I know how fat works. What I'm trying to start is more or less an experiment until I figure out what is good for me. Also 4000 is the maximum I can get my fitbit to with extra exercise normally I get closer to 3500 in a day. Even if that isn't right is is probaly in the ballpark.

I will try for 1000 deficit and double check my fitbit's accuracy. Just, do you know what my minimum to stay alive and not damage myself calorie intake would be? That's my main problem right now. Once I know that I can plan accordingly and make sure I'm not going to accidentally starve myself.

Thanks. Great quote by the way,

[FitBeforeFifty]

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@Fuzion_Reaktor wrote:

Just, do you know what my minimum to stay alive and not damage myself calorie intake would be? That's my main problem right now. Once I know that I can plan accordingly and make sure I'm not going to accidentally starve myself.

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The BMR number I gave you is the minimum needed to sustain your body functions at your current weight if you laid in bed all day long. That's not the minimum to stay alive, but who want's to get close to that threshold ? I don't know that there is any scientific evidence that eating below that will "damage" you but it's probably a good idea to stay above that calorie intake level. There are people that go on supervised weight loss programs that eat well below their BMR but the lower calorie intake the lower your nutritional value, so you have to be careful. In your case, eating 2500 calories (which is above your BMR) should allow you to get sufficient nutrition.

Personally, I see no need to eat even close to that low if you are active. My BMR is around 1500 calories. At my activity level, I can lose 1 lb per week eating around 2500 calories.

The other reason to avoid super fast weight loss is lean muscle loss. The faster you lose weight the more muscle you are likely to lose. A moderate rate of weight loss (1% per week) along with strength training will help mitigate muscle loss.

[JohnRi]

You and me are about the same height. I was 281, I'm 223 now.  So both need to be under 183 to be at the top of the healthy weight range.  The only difference between us I'm a 28 years older than you.  So I burn fewer calories a day due to age.  I will say that I used to burn 4000 calories a day according to my fitbit.  I usually ate 2500 or calories on those days, and I dropped 2-3 lbs a week.

But keep in mind, the heavier you are, the more calories you burn, and the easier it is to burn calories. 

I'm just 23 lbs lighter than you, and it's a lot harder now.  When you get to 40 lbs from goal, your BMR will have dropped quite a bit.  At that point you will probably have to drop to a 750 calorie deficit.  And down to a 500 calorie deficit at 20 lbs from goal.  And 250 deficit when you get to 10 lbs from goal. 

If you don't drop your deficit, your body tends to lose muscle more than fat at high deficits the closer you get to your goal.  No point of getting to the 170's and have 35% body fat, and no muscle strength.

Now your fitbit is probably over estimating your calories burn a little.  But a 2000 calorie deficit isn't very healthy, anything over 1000 isn't.  That being said, assume your fitbit is off by 10 to 20% of the calories your burn, so 1500 is probably safe until you get to 40 lbs from goal.  Then start increasing your calorie intake 100 to 150.. 

[Fuzion_Reaktor]

Thank You. That is what I needed and I'll shoot for that. give or take. 2000 definitely seemed too low unless all I did was lie aroundas you say. Now I must figure out whether or not I do burn as much as my fitbit says.