Guide to calorie deficits

Hello Folks,

So often people personal message me asking me if I think their calories are correct. It seems that people think there is some magical formula that only a very few can figure out. I see so many people on here just popping in numbers and following them heedless of what the numbers mean. I feel it's ULTRA important to know why MFP (and me, and a few others) gives you certain numbers. To that end I will try to empower YOU to be able to understand the basics about calories, calorie deficits, and why we recommend eating exercise calories. With this knowledge you should be able to easily figure out what your calories should be at for reasonable, healthy weight loss. So without further ado, lets get started.

1st things first, a few givens must be stated:

-Everyone's body is slightly different. ALWAYS keep in mind your numbers may not be exactly what MFP thinks simply because everyone's bodies all burn energy at a different rate. Tweaking may be needed.

- MFP's goals wizard is a "dumb" tool. That means it doesn't care whether a specific goal is healthy and/or right for you, it just subtracts the goal deficit from projected maintenance calories. This means that even if you shouldn't be trying for a 2 lb a week loss, MFP won't care, it will still try to help you get there.

-1200 calories is a generic number. It's not right for everyone. It's a baseline minimum given out as a floor by MFP based on prior research by the medical community. NOT everyone will need a minimum of 1200, very small people can go under, and bigger people need more.


OK with those facts firmly set in your mind (please go back and re-read the givens until you have them firmly planted in your skull!), we can continue. Figuring out your perfect deficit isn't magic, it's a few simple formula's base on some basic, worldwide standards, and generally with slight modefication, will work for just about anyone who (besides weight) is generally healthy.

Here's what you need:
Height, weight, age, activity level, sex

NOTE: activity level isn't as mysterious as it sounds. If you have a desk job, and do very little walking throughout the day and don't really perform any sports or physical activities, then you are sedentary, if you do some walking every day (or at least 4 days a week) or other light activity for at least 30 minutes cumulative at least 4 times a week, you are lightly active. If you do 60 minutes of light activity 5 days a week or do some kind of sport that requires walking or light jogging (say swimming or mailman or warehouse employee) then you are active, If you do a physically demanding activity (one that makes you sweat) for 4 days a week or more and for more than 1 hour a day, you are very active (like a coach that runs drills or you play volleyball). When in doubt, go down 1 level, you'd rather burn more than you think than less.

With all these numbers you can generate your BMI. Now I realize BMI is flawed, but for what we're doing it's good enough. After years on here, and doing lots and lots of research, I've been able to associate general BMI ranges with approximate goal levels. This works for about 80 to 85% of people out there (there's always a few that are outside the curve).

So now we can figure out where your goal should be.
Go to the tools section and figure out your BMI:

Generally someone with a BMI over 32 can do a 1000 calorie a day (2 lbs a week) deficit
With a BMI of 30 to 32 a deficit of 750 calories is generally correct (about 1.5 lbs a week)
With a BMI of 28 to 30 a deficit of 500 calories is about right (about 1 lb a week)
With a BMI of 26 to 28 a deficit of about 300 calories is perfect (about 1/2 lb a week)
and below 26... well this is where we get fuzzy. See now you're no longer talking about being overweight, so while it's still ok to have a small deficit, you really should shift your focus more towards muscle building, and reducing fat. This means it is EXTRA important to eat your exercise calories as your body needs to KNOW it's ok to burn fat stores, and the only way it will know is if you keep giving it the calories it needs to not enter the famine response (starvation mode).

With this quick guide you can figure out your goal rather easily. I know many people will say "I can't eat my exercise calories, I gain weight when I do". Well I have news for you, that's not correct. I submit this, if you eat your exercise calories and gain weight 1 of 3 things happened:
1 you were previously in starvation mode, and you upped your calories, and had an immediate weight gain, that's normal, to be expected, and necessary to get your body on track. Give it a month, that will stop, and you, once again, will begin to lose, but this time, in a healthy manner.
2 you incorrectly calculated something, either your exercise calories, your calorie intake, or you put in to large of a goal. Go back and check all your numbers.
3 you haven't given it enough time to work. This site promotes HEALTHY weight loss people. Healthy weight loss doesn't happen in days or weeks, it takes months and years. Each change you make in how you eat needs a month or more to work, be patient, give it time. It will happen.

And to everyone who has a trainer that doesn't agree with eating your exercise calories. I also submit this: In 90% of the cases (and I have talked to a LOT of trainers about this exact topic) they actually DO agree with this method, you just explained it wrong.
Just saying to a trainer "should I eat my exercise calories?" isn't enough, you have to explain to them that MFP already generates a deficit prior to any exercise, therefore the deficit will remain whether you exercise or not. Once you give them that idea, and you are relatively sure they understand the concept then I'll bet they change their tune.

I hope this helps, it's pretty straight forward if you've been here a while, and to you new guys, I recommend going to the message boards link, clicking on the "general diet and weight loss" area, and clicking on those first few posts that have the little mouse trap next to them, they are sticky and will always be there, and are a wealth of knowledge about this site, exercise calories, starvation mode...etc.

regards,

-Banks