Nutrient Partitioning: Not Every Calorie is Equal
Ever wonder why you stop losing weight (or body fat more precisely) a couple weeks into a particular dieting cycle. Why do some people tend to gain only fat and lose mostly muscle when they diet? How do some people only gain muscle when they workout and eat and then lose only bodyfat? Are there genetic freaks out there?
The answer to that last question is yes – but not many – surprisingly few. You’ve seen pictures of them on magazines, edited by photoshop and perfect lighting.
But what about the rest of us average folk that want to lose fat, gain a little muscle (because it boosts our metabolism and is, after all, sexy).
We have to realize that not every calorie is equal. There are some patients that are very sick, that I’ve taken care of in the ICU, that have needed close to 8000 calories a day to maintain body weight….and they are not moving! Why do some calories get shuttled to fat stores and some get shuttled to metabolic burning or to building muscle?
Nutrient partitioning is the process by which your body directs dietary energy (from protein, fats, and carbohydrates) to its ultimate destination. Your body will either burn this energy or store it. In the presence of certain hormones, you body will preferentially burn nutrients, or store them as muscle vice fat. Thus, a calorie really isn’t a calorie after all.
The main hormonal determinant of nutrient partitioning is insulin.
If you are overweight, your ability to partition nutrients has probably taken a little bit of a hit. You may even have some insulin resistance. If this worsens you could become diabetic. That is when nutrient partitioning is at its worst – and exceedingly difficult to recover from.
Insulin signals your body’s cells to allow nutrients to get in and be utilized (for energy, muscle growth, fat storage, etc.). If it can’t be transported into the muscle cell then any unneeded glucose is converted into fatty acids and placed for safe keeping in the fat cells in your belly, booty, other b words…and so on.
Rather than being insulin resistant from a lack of exercise (or even the wrong exercise), or from too much carbohydrates (or even the wrong carbohydrates) in your training and diet, if you have had just the opposite approach (resistance training, HIIT, some cardio, low glycemic carbs and protein timed appropriately) you will make yourself insulin sensitive. You will have found the holy grail of body metabolism.
How do you “Hack” this Nutrient Partioning thing?
Particularly when trying to drop unwanted body fat? Normally I am a 6 meal a day guy (all meals are 300-500 calories so they are not huge). Since I already know my meal sizes and have my favorites, to cut calories I just drop the first meal of the day….Boom! 300-500 calorie deficit created out of thin air. Here are my favorite Hacks:
- Drink a half liter of water first thing in the AM. Try to delay meal one until 0900 or so. If you have to eat early ensure it is high fiber, complex carbohydrate, adequate protein with some fat and shoot for that zone ratio of 40/30/30.
- Drink all of your coffee black and your tea unsweetened (may use an artificial sweetener if you must. Get used to it. Secondly, get used to it….
- Other meals throughout the day should have complex, low glycemic index carbs, again adequate protein, moderate good fats.
- Preworkout meal (2-4 hours prior to training). Moderate amount of carbs (may go moderate on glycemic index with no change in protein, a bit lower on fat)
- Post workout is the only time you consume high glycemic index carbs (about 50 g for avg sized adult), whey protein (high BCAA content), keep the fat content of your postworkout meal very low
- Prior to bed – meat or eggs, very low on carbs, high on fiber.
For more on what the glycemic index (GI) is, visit:
For a list of the GI of some of the most common foods:
In general avoid “white carbohydrates” (most breads, pasta, white potatoes, etc.) unless using specifically for sport specific reasons (endurance races). More whole grains, nuts, fruits and vegetables. Of course, avoiding candy, cookies, cakes, and sweet drinks (even juice!).
Lanny Littlejohn, MD