How Often To Eat?
Why Eating Frequently Is Terrible Advice For Most People....January 8th, 2013
By Brian Rigby, Clinical Nutrition Writer
Many RDs (registered dietitians) and other nutritional professionals recommend eating frequent, small meals over fewer, larger meals for weight loss. Is this really the best practice though?
The short answer is that depending on your goals and what population you fit into (e.g., healthy adult, overweight, athlete, adolescent, etc.), the best practice for eating differs. For most of us, we fall into one of the three most common populations: healthy adult (weight maintenance), overweight (weight loss), and athlete (maximizing body composition).
Our body has two important hormones for regulating our blood sugar, and by extension how we use any calories in general: insulin and glucagon. Insulin is an anabolic hormone, which means it helps our body "build up". This can be positive, as in muscle gain, or negative, as in fat gain. Insulin's primary goal is to get rid of excess glucose in the blood, which means either pushing it to the muscles to use as energy or storing it in the fat for later use.
Insulin: Our "Building" Hormone
Whether it provides muscular energy or gets stored is a product of your current situation--if you are working out (and you are not insulin resistant or have another disease affecting your blood glucose), chances are high that all of the carbs you ingest (up to about 60 grams per hour, our body's average maximum for carbohydrate oxidation) will be used for energy, not storage.
If, on the other hand, you've been sedentary all day, or have high glycogen stores and low energy needs, then this excess sugar will be converted into fat for storage (glycogen is how our body stores carbs, and we have very limited quantities of it).
Glucagon: Our "Breaking Down" Hormone
Glucagon, on the other hand, performs the opposite role. When our blood glucose starts dipping, it lets the body know to release more glucose from the stored glycogen to balance levels out. Our brain can only run off of glucose (with rare exceptions such as starvation) and so a constant, steady stream is vitally important to its function.
When glucagon is released, it also a signal to our body that we need to switch energy sources for other organs and our muscles from glucose to fat in order to preserve the glucose supply for the brain. This means that even though glucagon's primary purpose is to increase blood glucose levels, it also ultimately increases the rate at which we burn fat, at least when we are at rest or only engaged in light activity.
Things gets more complicated when you add in the differing goals of different populations and their different energy requirements. For athletes, who tend to have very low body-fat percentages to begin with and have high energy requirements, and who also want to continually build and restore muscle protein (which is broken down during their workouts), insulin is their best friend--but only in small, steady amounts. Since their energy requirements are high, it is unlikely the extra carbs ingested will be turned into fat (they will instead power the muscles), and maintaining a certain level of insulin will also ensure that their muscle proteins don't get broken down.
This is important because another effect of glucagon is to increase the rate of gluconeogenesis, which means our body starts taking more amino acids from our muscles (breaking them down) and converting them into glucose (once again, to help supply the brain). While this is unlikely to affect a non-athlete adult or someone trying to lose weight in a significant way, it can be the difference between making a quick recovery and making performance gains or not for an athlete. For this reason, athletes tend to perform best when they eat smaller, more frequent meals.
So why would an RD, even a very well-educated one, suggest to someone trying to lose weight to eat frequent, small meals?
The answer deals with something called the "thermogenic effect" of food. The thermogenic effect of food is how many calories it takes us to digest and absorb the food. While food ultimately provides us with way more calories than it takes to digest it, it does take a certain amount of invested energy for our body to process food and absorb it--the amount of calories burned in this manner is the thermogenic effect of the food.
It Takes Energy To Digest Food
Eating frequently is "harder work" for our body, which must invest more calories in order to render the food absorbable. Theoretically (and in practice for some populations, such as athletes), this means that at the end of the day, when all calories burned and eaten are tallied up, smaller and more frequent meals will render a lower total than large, infrequent meals, which suggests that for weight loss, this could be ideal. However, it is (as always) more complicated.
For an athlete, who is most likely not trying to lose weight, a higher thermogenic effect helps to optimize total body composition. For a 170 lb. male who wants to get stronger, this means that after a month of eating like this (and not over or under-eating), he will weigh the same (170 lbs) but have more overall muscle and less fat, a desirable outcome for most athletes.
In a weight loss situation, however, it is unlikely that most people would want to continue to weigh their current weight but replace all of the fat with muscle, especially if you have significant amounts to lose!
While it is still possible to lose weight using this method, the fact is that smaller, more frequent meals will always promote the release of insulin and discourage the release of glucagon, keeping your body in an anabolic state where it wants to "build" instead of "burn". Again, if you are very active, then building is good and will translate into muscle gain. On the other hand, if you are not very active, then much of this build will just turn into fat, and weight loss will be slowed or stopped.
Harnessing Glucagon To Burn Fat
For losing weight, stimulating the release of glucagon, our catabolic hormone, is a good thing as it helps the body release the fat it has already stored back into the blood where it can be burned by the muscles. For an athlete, this is not desirable because some of that weight lost will be muscle weight, and it will be challenging to make strength gains.
For somebody trying to lose weight, you just have to accept that some of that weight will be muscle weight, though the majority will be fat, especially in a well-designed program focusing on higher amounts of protein (25-30% of total daily calories). When protein is adequately high, our body has a different source of amino acids to oxidize and doesn't scavenge as many from our muscles (or they serve to quickly restore any amino acids that are scavenged). This enables people looking to lose weight to minimize losses in lean body-mass and maximize fat loss, which will overall render them stronger!
(To understand this, imagine running with a 50 lb. backpack on vs. running without one--you'll be much faster and be able to run longer without the backpack, so losing 50 lbs will have an overall effect of increasing strength, even if a few pounds of muscle are also lost)
By eating larger, infrequent meals, you do get larger spikes of insulin which will likely tell your body to store some of your excess energy as fat, but these are more than offset by the glucagon dips which tell your body to take that fat energy back out and burn it, and if you are carefully planning your meals then you will not supply your body with more energy than it knows what to do with.
This does, of course, rely on your diet being lower overall in calories than your normal requirements (but not in excessive amounts--only 10 - 20% under to prevent a slowing of your metabolism). Over time, you will see greater weight loss by "getting acquainted" with glucagon, which makes infrequent meals a generally better idea for those wishing to lose weight (though this will certainly continue to be debated!).
Finally, how about for just generally healthy adults with no weight to lose and who are not athletes? For them as well, not eating as often is probably the best idea for weight maintenance since their overall energy needs are smaller and they are more likely to store excess energy as fat in the case of the continuous insulin release caused by frequent meals (since they have lower energy requirements and are unlikely to need the excess glucose and fat to power their muscles).
To put it succinctly, unless your energy requirements are very high, you do not need insulin to constantly be telling your body how to use that energy!
It's A Balancing Act!
Ultimately, you want to balance the release of insulin and glucagon. For athletes, since they work out frequently and for extended periods of time, glucagon ends up being released in large amounts to help stabilize blood sugar--for them, a slow trickle of insulin is offset by their activities.
For those looking to lose weight or maintain weight, and who do not exercise frequently and for long periods of time, they need to balance their insulin-releasing moments (after meals) with glucagon-releasing ones (the delays between eating). If these populations ate frequently, glucagon release would be suppressed because they would never enter a situation where glucagon is necessary, and as a result, any fat stored would never have a good opportunity to be released, eventually leading to weight gain and increased fat mass.
Q: So bottom line maintain a weight loss mode...don't eat between meals? I found the info very interesting, but still a little confusing. I welcome more clarity. I am concerned about optimal weight loss and inflammation reduction right now. And I am on JJ's 3 week plan now. Week one almost done...so far so good! :)
A: For pure weight loss, the three-meal plan is best. With the Fresh Start Cleanse, your calories are already weighted favorably towards the best ratios for weight loss (45% carbs, 25-30% protein, 25-30% fat), so you don't need to worry about that during the two weeks!
If you exercise in the morning, I would recommend having the majority of your shake POST-exercise as it is designed to really keep you full, which is achieved in part by how it slows down the emptying of your stomach (with fiber and protein). This is great for satiety and even release of nutrients (no big insulin spikes!), but during exercise it can also slow down your absorption of water and lead to dehydration (not to mention causing you to potentially feel bloated, never pleasant when exercising!).
Q: What if you do a 30minute HIIT class two times per week, and on opposite days, do 1-1.5 hours swimming- some of it high intensity- I swim with the masters swim team- usually 1-3 times per week. I also do heavy weights to failure on the days I miss the HIIT- about 40minutes. Would this be considered an athlete? I am in the category of wanting to lose fat/weight.
A: If you do frequent high-intensity workouts, but they are of a shorter duration, then you may want try 'hybridizing' the plan so you aren't eating frequent small meals, but you are still providing your body with the nourishment it needs to experience gains is strength.
For example, if your workouts are in the morning, you may want to have a small breakfast about an hour to an hour and a half before your workout and then save your 'real' breakfast for afterwards. This way you don't go into your workout in a catabolic state (where your body needs to take amino acids from your muscles to produce more fuel), allowing you to perform your best. Afterwards, your larger meal will supply the necessary materials to ensure a rapid recovery. For the rest of the day, you would eat only every 4-6 hours for a total of three 'normal' meals and one small pre-workout snack to optimize training.
If you don't workout in the morning, it works just as well for afternoon or evening, just adjust your eating habits accordingly. The most important thing is that you don't train without supplying your body adequate fuel (this is important regardless of how much you workout), as this will cause you to lose weight in a bad way--by losing muscle!
Q: I'm a little confused as well. I'm on a diet but exercise hard every day. Do I consider myself an athlete or a dieter? Do I eat 5-6 small meals or 3 meals a day?
A: If you vigorously exercise for more than two hours at a time five or more days a week, then you will probably experience better results with more frequent meals. This is because your caloric expenditure will be so great that if you do not provide enough calories at the right times, your body will break down the muscle you are working so hard to gain to fulfill the deficit! For the average "casual" exerciser, who might exercise for an hour at a time a few days a week, the amount of calories burned is not enough to induce this same effect, so fewer meals will work better.
One other important point I'd like to make for your case is that your eating patterns will still be based upon your goals, even if you eat more frequently. For example, if you weigh around the amount you'd like (or is common for your sport of interest), but feel like a disproportionate amount is in the form of fat (and not muscle), then eating a diet which is isocaloric (or energy neutral--not too many calories or to few) will support a transition to a higher muscle mass and reduced fat mass without sacrificing any weight or muscle. If, on the other hand, you are heavier than you'd like to be, or heavier than the general norms for people who participate in the same sport, then lowering your total caloric intake by 10-20% will support weight loss without stimulating too great of a loss of muscle.
In either case, if you exercise long, hard, and frequently, you will support your body better by smaller, more frequent meals!
Q: The way i read the article, it is saying if you want to lose weight you shouldn't eat the small meals often because you want the glucogen effect to burn the fat for you - even if you are exercising hard out. The small meals are for those 'athletes' who have no reserves to call upon.
A:Yes, exactly! For the average person trying to lose weight, they need to release glucagon in order to burn amounts we would consider 'effective'. We're always burning fat to some small degree, but leveraging your hormones to burn MORE fat will increase your rate of fat loss and get you to your goal quicker!
Through frequent, vigorous exercise, athletes engage other hormones not covered in this article which ALSO stimulate the release of fat (in addition to promoting the release of glucagon). In this way, athletes end up burning a lot of fat even when they eat frequently, something that just doesn't happen unless you exercise enough!
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