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Weight Loss vs. Fat Loss, Pt. 2

Posted April 12, 2010 by

Now that we’ve identified that metabolism is the key to true fat loss (rather than simple “calories in vs. calories out”) the question becomes how to properly raise metabolism to most effectively support optimal fat loss while simultaneously reducing potential muscle loss.

As previously discussed, your metabolism is the amount of energy (in the form of calories) that your body uses on a daily basis. Other terms for this include “basal metabolic rate (BMR),” “resting metabolic rate (RMR),” and, when combined with the additional energy you use during your daily activities, “total daily energy expenditure (TDEE).”

Your TDEE is the most relevant value to focus on, because in order to raise your metabolism as high as possible, it is important to address both sides of the equation: your energy expenditure while “at rest,” and the activities you perform specifically to burn extra calories on a daily basis, such as cardio, athletics and resistance training. Your resting metabolism is determined mainly by the following factors:

  • the amount of lean mass you have
  • your nutrition
  • residual effects of high intensity cardio training

As we discussed in part 1, the more lean mass you have, the higher your metabolism will be because muscle takes a lot of energy to maintain. This is why it is critical to adopt a resistance training program if you want to successfully lose body fat—without use, muscles will atrophy (reduce in size). Your nutritional plan is important for many reasons, the most relevant of which to our discussion is that you need to get enough protein in your diet. This is for two reasons; adequate protein intake will reduce the chance of muscle loss, and protein is the most thermogenic macronutrient of the three. What I mean by that is, protein takes the most energy to digest, calorie for calorie.

What I mean by “residual effects of high intensity cardio training” is that when you properly perform high intensity interval training, your metabolism will actually be raised for the remainder of the day, not just while you’re actually working out. Thus, while you may burn 200-300 calories during your bout of cardio training, over the course of the day, your RMR will also increase, adding to the total calories you burn through the day.

What all this means is that by maximizing the amount of calories you burn—both at rest and through activity—you are able to eat more calories than you would with diet alone, while still remaining at a deficit. For example, if your maintenance level (the amount of calories needed to avoid gaining or losing weight) was 1,500 calories per day, with diet alone you would have to reduce your calories to about 1,000 which is very low and would likely lead to muscle loss rather than fat loss, even with a resistance program implemented. On the other hand, if you combine high intensity cardio training 3-4 days a week, proper nutrition and a resistance program, your maintenance level may rise closer to 2,000 calories per day. In this case, you wouldn’t have to reduce your calories at ALL from their normal amount (1,500) and would still be at a 500 calorie deficit, allowing you to lose approximately 1 lb. of fat per week.

Comments on Weight Loss vs. Fat Loss, Pt. 2 »

  1. Garet

    Hi Ben! First, great series of articles here!

    I was wondering about the idea of calories burned by muscle. I have seen the number of calories burned by one extra pound of muscle varying anywhere from 5 calories/day to 50 calories/day. Obviously, this is a huge difference and I was wondering if you had any insight as to what an accurate measurement is or if it is dependent on someones genetics, gender, and activity level.

    Also, I know that this didn’t come up in this article but somewhere else you said that the body actually doesn’t burn fat during exercise and that the “Fat Burning Zone” was a myth. I was wondering if you could elaborate on that, as if that is true, that is a pretty big deal!

    Thanks for the great information!

    Garet

  2. Benjamin Ballinger

    Hey Garet! Glad you’re getting some worth out of the blog 🙂

    From what I understand, calories burned per muscle is very hard to actually measure, particularly since everyone’s caloric expenditure is unique to enough of a level that drilling down to this level of measurement can result in wide ranges like this. After all, a 100lb female with 80% lean mass may burn a different number of calories per day than another girl of the same composition, all else remaining equal. Without more information, this points to a discrepancy between the number of calories metabolized by each to retain their muscle mass. This would also explain so-called mesomorphs, who seem to be able to eat whatever they want and still remain lean and muscular. And yes, activity level definitely plays a role as well—for instance Excess Post-Exercise Oxygen Consumption (or EPOC) has been shown to boost metabolism for many hours after a workout, and if done on a consistent basis would equate to a higher BMR.

    As for fat burning zone and whether your body burns fat, your body DOES burn some fat during exercise, but the point I was making was that the majority of calories burned are coming from carbohydrates (and by majority I mean like 85%+) for anyone who isn’t in ketosis (which is a whole different story). The “fat burning zone” is this marketing BS idea that exercising at 65% of your max heart rate will result in utilizing the greatest amount of fat for energy, and this isn’t true. While the RATIO of fat will be the highest with lower intensity exercise (although, still pretty dismal at somewhere between 5-10% of total calories), because the total calories burned is lower, the absolute amount of fat burned will be less.

    Here’s an example to illustrate what I mean. (off the top of my head I can’t recall the exact percentages of fat to carbohydrate use per heart rate zone, so I’m going to guess, but the point still stands)

    Frank does cardio two different days. On day 1, he exercises at 65% hr for 1 hour, burning 150 calories total, of which 15% of the calories come from fat.

    On day 2, he exercises at 85% hr for 30 minutes, burning 300 calories total, of which 8% of the calories come from fat.

    Day 1: 150 x .15 = 22.5 calories from fat
    Day 2: 300 x .08 = 24 calories from fat

    A couple things to note. Firstly, Frank burned MORE total fat in LESS time with high intensity exercise, thanks to the greater TOTAL calories being burned (even though the percentage from fat was less). Secondly, caloric balance is much more important to fat loss than any case-by-case energy system usage breakdown, and by that I mean, what’s most important is that you burn more calories than you eat… so a cardio style that burns MORE calories is going to ultimately be superior regardless of anything else (and in this case, he burned 300 calories with high intensity exercise instead of 150 with the low intensity).

    Hope that helps!

  3. Garet

    Thanks for the awesome response! Its great to get a nuance answer while also keeping in mind the fundamentals; like eating less than you burn!

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