Exercise & Nutrition Q & A - 10/5/2013

You've got questions, I've got answers. Ask what you will about Exercise, Nutrition, Cooking or WLS and I will do my best to find you an answer.

Can you recommend a good way to calculate your caloric needs?  I've seen a lot of on-line calculators, but they don't seem accurate for me.  I'm pre-op, trying to get in shape for surgery so I'll have an easier recovery.  All the calculators I've tried say I should be eating much less than I am, but my weight has been stable for over a year, so I know my caloric needs can't be that low.  I finally signed up for myfitnesspal this week, and I ate more than they recommended, but less than I normally do, and even going over their caloric recommendation for a loss of one pound a week, I lost four.  I know some of that's water, but it still seems odd.

MyFitnessPal is pretty good and you should listen to it because it works pretty well over the long term which means yes right now you may see a more dramatic and easier weight loss now but in a month and for sure a year it will slow down quite a bit. MFP takes your long term goal into account and calculates based on that.

That being said and you are not going to want to hear this but your actual caloric needs are probably much lower than even the calculators are telling you. These calculations are based on your Resting Metabolic Rate and there seems to be a couple of ways to calculate that. I have done a couple if them and my resulting RMR from those calculations range has differences of over 500 calories. Further those calculations are based on an average on do not take into account your current fitness level.

I use a body composition scale to calculate my RMR and it is currently reporting it at around 1920, but the calculators report between 2250 and 2800. So if I went based on the calculators I would eat 300 to 900 MORE than I really should. Another thing that the calculators do not take into account is your resting heart rate which comes down the more weight you lose and the more cardio you do. My my resting heart rate is now about 58 where at my heaviest it was well over 90. So sitting around when I was 384 I burned more calories than I do when I warm up now and it takes a significant jog to reach that level.

To further complicate this you need to know how much weight you want to lose. 1 lb is about 3500 calories so if you want to lose 2 lbs per week you need a caloric deficit of 7000 calories or 1000 calories per day. So if your resting metabolic rate is 2500 that means you can eat 1500 calories if you do not do any exercise. If you burn 500 calories from exercise then you can eat 2000 calories. But 500 calories from exercise is a lot harder than it sounds. 

Whatever the calculators tell you, I would drop it down by about 20% to tell you what you really need to be successful. After surgery you will approach this differently and will manually set your goals in MFP. You will eat 600-800 calories per day, under 40 carbs, and get as much exercise as you can.

This is pretty consistent with what I have experienced on my own plan as well. The cruel irony is that as I approach goal the calorie deficit is harder to maintain, so less loss. For example If I have a good walk over and hour I can burn 400 calories, but someone half my size may only burn 200 calories for what appears to be the same level of effort. Never the less consistent exercise is necessary and improves overall health so it is still very important to my plan.

What you say make sense.  I should need to eat less than the calculators say to lose weight since I'm not very active due to orthopedic issues and I've lost weight before, which new research says slows your metabolism for years, but I eat more without gaining.  My math has to be wrong somewhere.  Maybe I'm overestimating what I eat?  I know most people underestimate their caloric intake, but based on every estimate I've seen, I can't be eating as many calories as I think I am and maintain at this weight.