basal metabolic rate

“That’s a good question. In my office, I work everybody via a single method. My scale tells me what their basal metabolic rate is, and this is something that’s calculated from their skeletal muscle mass, etc. The scale does this calculation and generates a number, their basal metabolic rate. Typically, what I’ll do is use a modified ketogenic diet, not a full ketogenic diet, in my office.

A modified ketogenic diet is the way that people can basically exist long term. Obviously for my morbidly obese patients, I do use a classic ketogenic diet with a slow induction phase, but for my modified ketogenic diet – where everyone should essentially be living from the standpoint of health and not shedding muscle – that is typically between 50 and 100 grams a day. Most of my patients are somewhere between 75-100g unless I have a very, very petite individual frame wise, in which case I may start them off at 50. But 75-100g of carbohydrates is where I start them, and then I work backwards from their basal metabolic rate. So 4 calories or kilocalories per gram of carbohydrate, then I’ll start subtracting off.

What I’ll do with protein and fat loads is as follows: I’ll use their lean body mass, which is something that is calculated on the scale and it’s really easy to calculate at home. All you have to do is, once you have your body fat percentage, and you can get that with calipers if you’re good with calipers or a DEXA study. What you want to do is, you want to subtract your fat mass from your total body weight, and that’s gonna give you your lean body mass. I will typically use one gram of protein per pound of lean body mass, per day. Then I’ll multiply that number by 4, now I have my carbohydrate calories, my protein calories and the rest will be made up in fat.

What ends up happening is that the modified ketogenic diet that I use, unlike a ketogenic diet, is typically about 50-55% of their daily calorie intake is from fat, and that’s really independent of their body mass because everything sort of fills in itself if you go through that math. Some people are a little bit more, some people are a little bit less, but it’s somewhere around 50-55% of their daily calories. So with me, there’s not so much of a balancing act that has to be done.

If you are very, very concerned about losing muscle and losing fat, or maintaining muscle and losing fat, then there’s, to some degree, a balancing act. The way that you solve that problem is you make sure that you’re eating at your basal metabolic rate at the very least, and I will set my patients at their basal metabolic rate, not more, not less. I have them stimulate their metabolism by eating small, frequent meals. Then, if need be, I will start fiddling around with their macro nutrients in order to attain the desired effect. But what you don’t want to do is create a caloric deficit because you’re going to end up shedding muscle.

What you should do if you feel that your energy levels are waning, is take a look at your macro nutrients. Make sure that you are getting enough calories in during the day, and you can always use exogenous ketones or MCT oil in order to push those fat calories up a little bit and that’s gonna give you energy and better your fat burning. If you want to stay in that fat-adapted state, I wouldn’t really push too much on the protein side because you tend to knock yourself out of ketosis by taking too much protein in. Instead, if you feel a lull, or if you want to stimulate more fat burning, I would instead recommend that an individual just slightly nudge up their fat calories and not show your body any more insulin signal.

The answer to your protein and your fat balance is, I would err on the side of playing more with the fat calories as opposed to playing with the protein calories. There’s a tendency in fat-burning phases to knock yourself out of ketosis and your fat is going to come off slower, so you have to be careful. Again, I will always, always, always default to a personalized sort of approach. You have to figure it out for yourself by checking frequently and testing frequently. If you just have access to skin calipers, fine, use a skin caliper. Keep an eye on your body fat and then fiddle around with your macro nutrients. For sure, I would absolutely leave the carbohydrates alone if you want to stay in that fat-adapted or even that ketosis state. If you start going up above 100g even, you’re going to notice that you’re not even showing up on the scale of the keto sticks or on the blood.”

Dr. Brett Osborn

Dr. O is a Team BPI Sports’ fitness and nutrition expert.