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Appetite For Construction
Feb 22 2002

By Dr. John M Berardi, Ph.D.
First published at www.t-mag.com.

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When and When Not to Eat Carbs

Q. Is it smart to keep carbs very low in the first and last meal of the day to aid in fat loss? Would that change if a person's goal was strictly mass gains?

A. There are dozens of ways to get lean. But I'll make it easy on you. Simply put, the general rules for how to eat before bed and when you wake up are as follows.

1. Avoid big, high-insulin carbohydrate meals before bed; save those types of carbohydrate for the post-workout period only. Of course, if you train late at night, it's okay to eat big insulin-releasing carbohydrates before bed; you'll need them for recovery.

Either way, there should be a pre-bedtime meal and it should definitely contain some protein and, depending on your exercise, the carbohydrate and fat content will vary. If you haven't exercised at night, then avoiding most carbohydrates before bed may be your best way to lose fat.

2. In the morning: Eat as soon as you get up. This meal should contain a good amount of protein. While avoiding carbohydrate at this point will also help accelerate fat loss, the trade off may not be worth it since the overnight fasting period surely may have depleted some of your muscle and liver glycogen stores. As a result, most people feel low in energy and in addition, workouts will suffer.

Therefore, perhaps the two best times of the day to include carbohydrates when trying to lose fat are in the AM and after working out. The AM carbohydrates should be fibrous and low on the glycemic and insulin indices while the post-exercise carbohydrates should be high glycemic and insulin releasing.

If your goal is strictly mass gain, the nighttime rules still apply. However, for the reasons above, it's a good idea to have more carbohydrates in the morning and throughout the day to replenish what was spent over night and prevent further use of stored energy.

Emptying the Fuel Tank

Q. What exactly is a "glycogen depleting workout" and why should I do one?

A. Let me first describe what glycogen is and how important it is to exercise performance. In essence, glycogen is the body's storage form of carbohydrate. Carbohydrates that you eat are digested and broken down into glucose and other simple sugars. After this occurs, the sugars, just like any other molecule that gets through the gastrointestinal wall, are sent to the gatekeeper, which is the liver.

Since the liver is also the blood's glucose regulator, it takes what it wants for storage by arranging the individual glucose molecules into long chains. These chains are called glycogen and the liver can store about 100 grams of it. Therefore, if completely depleted, the liver could store up to two full servings of Biotest Surge, leaving nothing for the muscles.

Whatever the liver doesn't store as glycogen, it kicks out to the blood in the form of glucose. And this glucose travels to different cells of the body (brain, organs, muscle, adipose) to provide fuel. Ideally, as much of this glucose as possible will end up in the muscle while very little will end up in adipose tissue. While being a good source of fuel for the muscle, this glucose is also, like in the liver, stored as glycogen. The body can store about 400+ grams of glycogen (depending on how muscular you are).

Now that you know what glycogen is, let's talk about depleting it with exercise.

Any form of exercise requiring at least a smidgen of effort requires the use of carbohydrate for energy. So, if you were the body, which source of carbohydrates would you choose? Would you choose to fuel the muscles with blood glucose? Or would you choose to fuel the muscles with stored glycogen?

I hope you said muscle glycogen because that's the right answer. Doesn't it make sense to use the carbohydrate that's available where the energy is needed (the muscles) and leave the stuff that the brain needs alone? Sure it does.

Any continuous exercise effort (endurance/cardiovascular type exercise) over 40-50% of VO2 max (about 65-70% of heart rate max) requires the utilization of more carbohydrates than fat. As exercise intensity and duration increases, more glycogen will be used. Here's an example:

QUADIRCEPS ENDURANCE

*Approximate values.

**Above 75% of max, fatigue sets in quite early. At 90% of max, subjects fatigued at 30 minutes while at 120% they couldn't go beyond 2 minutes (these were highly trained endurance athletes).

As indicated above, at the same duration, the more intense the exercise, the higher percentage of carbohydrate and the more total carbohydrate is used. In fact, if the effort is over 100% of VO2 max (as in sprinting or weight lifting), almost 100% of the contractile energy comes from carbohydrate. Check out these data:

So it appears that you can deplete muscle glycogen by either endurance-type exercise or anaerobic type exercise. Therefore if you want to deplete glycogen, pick your poison. Go ahead and exercise continuously for 60 minutes at 75% of your VO2 max (about 84% of your heart rate max), do repeated 1-2 minute intervals at 120% of your max (simply exercise as fast as you can for 1-2 minutes with an equal rest period between intervals), or go do 10 sets of 10 reps under a heavy bar with minimal rest between sets. All three will deplete muscle glycogen quite well. But why do that?

There are a few scenarios in which glycogen depletion exercise would be of benefit.

1) First, by training to deplete muscle glycogen, the body adapts to this type of training by learning to store more glycogen than it ever would have before. And since glycogen carries water with it, the muscle stores more water. If you're an endurance athlete, the glycogen and water increase will lead to more local energy stores and better hydration. If you're a weightlifter, this means more muscle volume (size).

2) Another reason a glycogen depletion workout would be of benefit is if you're getting ready for a big dietary cheat day. By doing a thorough total-body glycogen depletion workout (lots of sets and reps for several body parts with low rest intervals between sets), the body will preferentially store carbohydrates as glycogen in the liver and muscle. Therefore, by emptying the storage depots, you make more "room" for the binge.

3) Similarly, another good reason why you might do a glycogen depletion workout is if you're preparing for a low carb/ketogenic diet. Since the onset of ketosis usually occurs when muscle and liver glycogen get extremely low, doing a glycogen-depleting workout at the beginning of your diet will help you reach ketosis faster. But once in ketosis, hard workouts that are normally glycogen depleting are next to impossible since you simply wont have the carbohydrate energy to work that hard.

4) Finally, athletes will do a glycogen depletion workout several days before a big event so that the muscle can super compensate with carbohydrates. Basically, by eating a lower carb diet than usual and doing a tough workout, the muscle gets depleted of glycogen. Then once the athlete tapers down and stops exercising 2 or 3 days out from an event, they begin eating a very high carbohydrate diet that leads to super compensation and enhanced endurance the day of the event.

Too Fat to go on a Mass Phase?

Q. You've written before that going on a mass phase isn't a good idea for a person who isn't already lean because this leads to rapid fat gain. So how lean should a person be before cranking up the calories?

A. Based on empirical results (what I've seen in the gym) and the research I've discussed in a previous column, it's clear that one of the biggest determinants of your muscle loss to fat loss ratio (when dieting) and your muscle gain to fat gain ratio (when bulking up) is your initial level of body fatness. Generally, the amount of body fat that you have (percentage and total pounds of fat) will be a major determinant of how your body responds to over-eating or under-eating. Stated another way, if you're fat, you shouldn't try to bulk up because you'll gain mostly fat. But how much body fat puts you into the "too fat to bulk" category?

As I pointed out in one of my previous columns, subjects who started overfeeding with 22 lbs of fat on their bodies gained 70% of their weight as lean body mass and 30% of their weight as fat mass (To put this into perspective, your stats would have to be something like 150lb at 15% or 200lb at 11%).

However, double those body-fat numbers (150lb at 30% or 200lb at 22%), and the ratio flops in the opposite direction (30% lean body mass gain and 70% fat gain). With these data, it doesn't take too much of a leap to deduce that the 50-50 point would be around 33 lbs of fat (150lb at 22% fat; 200lb at 17%).

Now that you have these numbers, it's your turn to decide what's too fat to bulk. Ideally a 100% lean body mass gain is what we're all shooting for. But that isn't very realistic. In my opinion, a 70% lean to 30% fat gain is as far as I'm willing to go. And this fits right in line with my stats as I normally fluctuate between 5% fat and 12% fat throughout the year.

Therefore, I'll begin an overfeeding phase at 5% and bulk up to 10-12% fat. At this point, I begin to dislike how my physique looks. Conveniently, according to the data, the lean gain to fat gain ratio begins to decrease and more fat would be accumulating should I continue to overfeed.

But I'm partially lucky as I was blessed with decent "leanness" genetics. I know people who've never seen 5% despite valiant efforts. For them they may need a more liberal standard to follow.

Now that you're armed with the information, go ahead and decide for yourself what's "too fat to bulk" based on the projected fat and lean gains derived from your own weight and body fat percentages.

Eating Frequency: A Timely Issue

Q. Hey, John, there seems to be a trend emerging (at least with some bodybuilding mags) in less frequent eating, especially while dieting. What do you think of this? Is frequent eating a fad about to be replaced?

A. The quick answer is that I don't believe infrequent eating to be the dietary technology of the future; the frequent eating "fad" will not be replaced anytime soon. Let's look at a few specific examples of why eating frequently is my story and why I'm stickin' to it.

In hard-training athletes or bodybuilders interested in supporting their training or increasing their muscle mass, a low frequency of food intake doesn't make any sense and we don't even have to go to the research to figure this out. Think about it; for the athlete requiring 5,000 kcal per day, eating 2 x 2,500 calorie meals as opposed to 6 x 830 calorie meals is not only ridiculous, it might be downright impossible from a practical point of view. Let me ask you a question. Have you ever taken down a Chinese buffet? If so, would you be able to comfortably do that twice per day, every day, and still conduct your daily activities? I think not.

But besides talking only about practicality, let's talk physiology. In hard-training individuals, a continual fuel supply is required throughout the day to fuel both exercise performance and recovery from that exercise. This is best supplied with regular feeding intervals since the athlete's goal should be to preferentially replenish muscle energy stores rather than adding to their fat stores.

Large feedings will end up overloading the metabolic and hormonal systems, causing much of the caloric surplus (whether the energy comes from carbohydrate or fat) to be stored in the fat cells for later use. The problem here is that many athletes as well as weight lifters use predominantly carbohydrates for fuel and therefore the stored fat is useless in promoting performance enhancement or positive body composition changes. Eating infrequently is the worst thing an athlete interested in increasing performance or muscle mass can do.

But what about athletes interested in weight loss only? Well, infrequent feeding presents the same problems as above. Let's go to the research on this one. In a study done on boxers and published in the Scandinavian Journal of Medicine and Science In Sports (1996), 12 boxers received a hypocaloric, 1200 kcal per day eating program. Six of the 12 received this caloric intake in two meals while the others received this in six meals.

Although there was no in difference in body weight between the two groups (they all lost weight), the decrease in lean body mass (LBM) was significantly greater in the two meal group than in the six meal group. In addition it was shown that the two-meal group had a higher level of muscle protein breakdown than the six-meal group. So if you're training, dieting, and eating infrequent meals, you'll lose the same amount of weight, for sure. But the loss will be more muscle and lean body mass and less fat mass.

The next important question to ask yourself is this; why, if these diets make no sense, are the mags promoting them? Well, it's simple. Magazines thrive on novelty. The more "revolutionary" a program seems, the more excited readers get and the more subscriptions the magazine sells. Solid, time tested and proven training and nutritional information doesn't seem to get anyone excited any more. So new, unproven programs begin to dominate the pages of magazines.

But in looking at the new infrequent eating bandwagon, I see one other factor at work here. If you take the average trainee who goes to the gym an average of three days per week and doesn't pay much attention to what he's pumping into his physiological gas tank, you'll find that his 3 hours of exercise per week do not separate him, metabolically speaking, from his sedentary neighbors.

In addition, since he's eating his meals in what might be called irregular intervals, and when he does eat, he's eating predominantly empty calories (and loads of them - uh, he can afford it, he exercises, ya'know), he's ending up in a major fat storage situation. Now, if you can get this guy to eat better foods and a lower total calorie intake by convincing him that he's really a caveman on the inside and that the prehistoric beast is waiting to come out (or by whatever other little motivational method you use) he's going to get leaner; but not any leaner than if you would've just had him eat smaller, frequent, nutrient dense meals.

In fact, a study done in 1997 and published in the British Journal of Nutrition reviewed dozens of studies, showing that there's an inverse relationship between people's habitual frequency of eating and body weight. This means that the people who ate more frequently (the grazing-type eating pattern) tended to be leaner than infrequent eaters.

In 1981, a study published in the British Journal of Nutrition raised another important point. In this study, 38 obese patients followed a hypocaloric diet regimen that used either frequent or infrequent feedings. The researchers found that a diet with a high-protein concentration - fed as frequent small meals - is associated with better preservation of lean tissue than an isoenergetic diet (same amount of calories) with lower-protein concentration fed as fewer meals.

Interestingly, there was no evidence that meal frequency or protein concentration affect the rate of fat loss. So although you might be able to lose weight on a diet with fewer meals, you will lose more lean mass. And when it's time to come off the diet, the fat will return with a vengeance.

So, don't fall for the dietary trickery that's promoted in the name of magazine sales. In the end, using the physiological principles that support time-tested, research-proven dietary methods will lead you to the results you want. Sure, once in a while, a new and valid theory springs up from out of nowhere and revolutionizes the way we do things. But this is certainly not one of those times. Especially since this "infrequent feeding" idea isn't new at all. It's the picked over skeleton of a previously ineffective way of doing things.