Excess Protein May Cause You To Burn More Fat
My 'warning' is no exaggeration.
If you consume an 'excess' of protein, i.e., more protein than you need to build muscle with, you can actually burn more fat (e.g., Forslund et al., 1999). You can also achieve that thick, 'granite-hard' look to your muscles that so many people find to be unattainable when using other eating approaches.
By the end of this article, you'll know exactly how to use protein as a fat-burning 'torch' and you'll be well on your way to leaner, harder muscles.
This article was inspired by a question that I recently received: Rob, is it true that it doesn't really matter what you eat, it's the total calories? It is more than a case of 'calories in, calories out'. If anything, it is a case of macronutrients in, macronutrients out.
Protein, carbohydrate and fat comprise the three macronutrients in your diet. How many calories you consume of each ultimately determines whether you are getting leaner or fatter at any given moment. (NOTE: If you really want to master the 'art' of macronutrient balance, please read my article "Macronutrient Balance". I promise that it will change the way you look at eating, insofar as building muscle and losing fat are concerned, forever.)
A given amount of calories consumed as, for instance, 60% protein, 20% carbohydrate, and 20% fat -- a macronutrient profile not at all uncommon for me-can have a fundamentally different effect on body composition than the same number of calories consumed as, say, 30% protein, 60% carbohydrate, and 10% fat. In fact, I can practically guarantee that each of these macronutrient profiles will affect your body composition differently over the long term.
It has been my experience that an 'excess' protein, lower-carbohydrate eating approach works exceptionally well in this regard, particularly in terms of its effects on apparent muscle hardness, or 'density'.
Your Glucose Economy
This has to do with your Glucose Economy, as I call it. The Glucose Economy is my 'unified theory' of dieting. It's far from proven, but it certainly can explain a lot of things. Glucose is 'High Man' on the Totem Pole of Fuels. Your body deals in multiple 'currencies' of fuel, namely, carbohydrate, fat, and protein. Guess which fuel is your body's favorite? Carbohydrate -- in particular, glucose (a.k.a. 'blood sugar'). Yes, bodybuilders and non-bodybuilders alike often frown on carbohydrate; your fuel-burning metabolism, however, smiles on this macronutrient. Indeed, glucose is 'high man' on the totem pole of fuels burned, or oxidized, by your body.
The conventional definition of 'dietary carbohydrate' includes sugars, starches and fiber. Sugars and starches are the most common sources of glucose in the diet. They are also the most direct, and therefore, the most metabolically efficient, means of delivering glucose to your body. Starch, after all, consists of chains of glucose molecules linked together. Most dietary sugars (e.g., fructose, maltose) can be converted into glucose, and glucose... well... it already is glucose.
What all of this means is that it doesn't cost your body much energy to turn the sugars and starches so common in today's foods into glucose.
The 'See Saw' of Your Fuel-Burning Metabolism
Your body's top metabolic priority in achieving homeostasis is to preserve its overall supply of glucose, i.e., its Glucose Economy. The more carbohydrate you consume, the more glucose you burn. Simultaneously, you burn less in the way of fat. Conversely, the less carbohydrate you consume, the more fat you tend to burn (Flatt et al., 1985). This is your body's way of trying to preserve its dwindling Glucose Economy for tissues in need. You see, some tissues just can't do without glucose; for them, there is no substitute. If that's the case, then how is it that you can survive on a 'zero-carbohydrate' diet? How is it that you can survive without eating (not indefinitely, but for quite some time)?
The answer is both protein and fat can be converted (albeit very inefficiently) to glucose.
Let's consider protein. Protein consists of chains of amino acids. A great many of these amino acids (especially glutamine and alanine) can be converted into glucose. Now let's look at fat. The most common form of fat you eat (and stored on your body) is triacylglycerol. Each triacylglycerol molecule consists of a glycerol molecule attached to three fatty acids. Glycerol can be converted into glucose. Finally, let's consider lactic acid. Glucose is stored in your muscles as glycogen. During intense exercise, such as your workouts, muscle glycogen is broken down to form lactic acid. In fact, your muscles and other tissues release lactic acid all day long. It's just that it accumulates during intense exercise, because it is being produced so quickly. Like glycerol, lactic acid can be converted into glucose. (NOTE: As you can see, the claim made by your high school biology teacher that your muscles can't 'share' their glucose with other tissues isn't exactly true.)
Making glucose 'from scratch'
So, you see, no diet is truly 'carbohydrate free'. If you are eating food, then you are eating macronutrients capable of being converted into glucose, your body's favorite fuel, and a carbohydrate if there ever was one. If you aren't eating food, then your body can turn amino acids (supplied by the breakdown of tissue proteins), glycerol (supplied by the breakdown of body fat), and lactic acid (released from muscle and other tissues) into glucose. The process by which amino acids, glycerol and lactic acid are converted into glucose is termed gluconeogenesis. Gluconeogenesis occurs in the liver, as well as in the kidneys. It goes on all day long, even when you are well fed (Jungas et al., 1992). Gluconeogenesis involves work -chemical work-- and work consumes energy. Guess what? The energy required to drive gluconeogenesis is supplied by the burning of fat; that is, these two processes go hand-in-hand (Jungas et al., 1992; Morand et al., 1993).
Sometimes 'waste' is a good thing: 'Excess'-protein diets
All of which brings us to the body building benefits of an 'excess'-protein, lower-carbohydrate eating approach. Only a relatively small amount (e.g., 6-15 g) of amino acids is required to stimulate muscle protein synthesis, whether at rest or after your workouts (e.g., Børsheim et al., 2002; Paddon-Jones et al., 2003). Furthermore, some researchers provide compelling evidence that a sustained elevation in blood amino acid levels may not maintain muscle protein synthesis for longer than 120 minutes (Paddon-Jones et al., 2003. So why consume more protein than the small amount you require for building muscle? Why not just consume the additional calories you require as carbohydrate -the most direct form of glucose available?
One of the key reasons is that eating an 'excess' of protein can, when coupled with a reduced intake of carbohydrate (i.e., sugars and starch), reward you with a powerful fat-burning advantage. This 'anti-conventional' eating approach makes your metabolism work for its glucose.
Prehistoric diet = metabolically inefficient
50,000 to 100,000 years ago, when BodyMuscle was still being painted on the inside of caves, the food we ate was probably relatively whole, or unprocessed. Contrast that with the surplus of heavily processed foods that we have today, many of which provide your body's favorite fuel -glucose-in the most readily bio-available form you could possibly imagine!
Indeed, the typical modern diet allows your metabolism to be 'lazy', or at least, get less fat-burning 'exercise' than it otherwise could. That is, you could be burning substantially more fat, 24 hours a day, 7 days a week, simply by eating in a way that exploits your metabolism's capacity for gluconeogenesis.
Eating a diet consisting of nothing but fresh, whole foods -'back to Nature', as it were-can be very time-consuming. I work at home -my 'office' is the kitchen table. My girlfriend, Joy, cooks fresh steak and chicken breast meat for me every few days (yes, I'm spoiled). Still, I find that preparing more than 2 whole-food meals per day is just too time-consuming if I want to achieve all of my goals for the day. The other 3 meals I consume each day are protein shakes.
Nevertheless, by keeping my dietary carbohydrate intake low (~15-20% of calories), and my protein intake in 'excess' (~50-60% of calories), I am able to enjoy a substantial fat-burning advantage over metabolically 'lazy' diets providing less protein and more carbohydrate -but the same total amount of calories (if not less). No matter what kind of eating approach I try (and I've conducted some pretty extreme dietary experiments!), I always come back to this one.
Yes, you can get very lean and muscular with a virtually endless variety of macronutrient profiles. There is no one 'best' diet.
The calorie-burning effect of diet may only contribute modestly to daily energy expenditure -in the range of 3-10%, or roughly 80-200 calories, according to some estimates. However, every bit counts, in my book. In fact, an increase in fuel substrate (e.g., fat) oxidation too small to be detected with indirect calorimetry (a commonly employed method of measuring metabolism) can still be enough to bring about a loss in body fat if sustained over the long term.
"Since obesity, with its co morbidities such as the metabolic syndrome and cardiovascular diseases, is one of the major biomedical problems of the last few decades, efficient, effective and satisfying treatments are necessary. We hypothesize that elevated protein intake may serve this purpose because of its contribution to storage of fat free mass (2), its low energy efficiency during overfeeding (3, 4), and its increased satiety effect despite similar energy intake (5)."
The 'Stock hypothesis' states that during overfeeding a relatively high percentage of energy as protein might have a limiting effect on body weight gain in humans through an energy inefficiency effect (3,4).
Simpson et al. (2003):
"The results from this second phase of the experiment suggest that humans balance macronutrient intake, with protein intake being more strongly regulated than carbohydrate+fat intake: in the case where protein was in excess, subjects under-ate carbohydrate+fat rather than over-ingest protein, while when protein was in deficit, they over-ingested carbohydrate+fat rather than under-eat protein. This interpretation also accords with reports that protein is the `most satiating' of the macronutrients (Simpson et al, 2002; Stubbs, 1998), and that means protein intake varies the least of the macronutrients across human populations and with time, typically comprising between 11 and 15% of dietary energy (Westerterp-Platenga, 1996; Theall et al., 1984). Also consistent is the fact that weight loss occurs on diets containing a high percentage of protein (defined as greater than 25% of total energy intake), and that this is due mainly to the reduction of energy intake resulting from a failure substantially to over-consume protein (Eisenstein et al., 2002)." (emphasis mine)
How's this for an anti-conventional eating approach?
To sum things up, if your goal is to lose fat, you should encourage your body to use the protein calories you feed it inefficiently. As noted above, provided you don't eat too much carbohydrate and too many calories overall, much of the excess amino acids you consume can be converted into glucose via gluconeogenesis - a process fueled by the burning of fat. Thus, there is a solid thermodynamic argument as to why eating an 'excess' of protein can give you a significant fat-burning advantage.
Below is a sample of my own daily diet. I eat practically the same thing every single day of the year.
6'1" -- 210 lb. I eat about 2800-2900 calories per day, as 50-60% protein, 15-20% carbohydrate, and 10-20% fat.
(after morning workout) For this meal,
I use my blender to prepare a high-protein shake consisting
of a low-carbohydrate meal replacement (providing no more than
24 grams of carbohydrate and 40-45 grams of protein) 1 scoop of
Ultra Size, 1-2 scoops of Muscle Provider, 1 cup ice 1 tablespoon
psyllium husk (for fiber)
(usually about 1-1:30 P.M.): chicken breast, steak or roast (sirloin),
egg whites (6), and broccoli.
(about 5 P.M.): high-protein shake (same as Meal 1)
(about 8 P.M.): same as Meal 2
(before bed, about 10:30 P.M.): same as Meal 1, but with less carbohydrate
(I use only ½ of a low-carbohydrate meal replacement)
Most of us modern humans don't exercise our bodies enough physically or metabolically. There is a very solid thermodynamic argument as to why you can burn more fat 24 hours a day, 7 days a weak by 'exercising' your metabolism with an 'excess'-protein, low-carbohydrate eating approach. In an effort to preserve your Glucose Economy, your body will increase the rate of gluconeogenesis, thereby increasing your fat-burning rate alongside. No matter how hectic your lifestyle may be, you can find a way to follow this eating approach year-round. Protein powders, and low-carbohydrate meal replacements, because of their convenience, are especially helpful here.
REFERENCES ON REQUEST.