Hunger
We’ve seen in the basics that a calorie deficit is necessary to lose fat.
This means you have to eat less calories than you burn on average, daily, until you’ve reached your fat loss goal. Then you can eat the same amount of calories that you spend to maintain your weight (again, on a daily average). This means that you are exposing yourself to hunger, and if you do not deal with it, you will fall off the wagon sooner or later.
Hunger comes in different forms, depending on what is causing it. Addiction to sugar causes the worst cravings, but a depleted supply of glycogen in the liver will cause a low-intensity, annoying hunger sensation that ultimately gets the best of you. Ever heard of the waterdrop torture? The poor fellow that is subjected to this simply has a drop of water drip on his forehead every second. At first, it does nothing. It even sounds like a joke.
But after 24 hours, those drops of water will drive him crazy. Completely and hopelessly crazy.
That low intensity hunger is similar. It gnaws at you all the time until you give in.
Hunger is caused by a hormone called ghrelin. It is secreted by the pancreas when the hypothalamus detects low blood sugar, by the liver when its supply of glycogen is depleting, and by the stomach when it is empty.
There is another cause for hunger which is purely psychological. It comes in two forms:re-inforcement or punishment.
Both of these causes develop eating habits. Re-inforcement tend to make you repeat actions that lead to pleasurable outcomes (like eating something tasty). Punishment tends to make you reject actions that lead to unpleasant outcomes (like guilt, or rejection of your appearance which you associate to eating). Punishment can lead to eating disorders like anorexia, because eating is associated with a negative self image.
In most cases, realizing how psychology leads you to eat too much allows you to take conscious action against it. Not giving in to it for a while erases the habit.
But then there is the rest.
Low blood sugar and fat loss.
Low blood sugar often comes as a result of high blood sugar. The pancreas reacts with a strong secretion of insulin which causes the blood sugar to take a plunge. This causes the craving for sugar that leads to the next sugar high, and the cycle continues, strengthening the pancreas’s ability to secrete more insulin and therefore making the sugar lows (and cravings) worse. This becomes an addiction to sugar.
Stabilizing sugar intake will cool down the pancreas, leading to the addiction wearing away. This is done with a high fiber diet (fiber slows the absorption of sugar and fat), and by replacing fast sugar (foods with a high glycemic index) with slow sugars (vegetables like beans and peas or fruits like apples).
Note that not all fruits have a low glycemic index (actually, most are high). Apples have a low index thanks to the soluble fiber they contain.
Keeping your stomach full for fat loss.
An empty stomach remains an important factor in the hunger sensation, even if it isn’t the only one, or the most important. Keeping your stomach reasonably full definitely helps, but it needs to be done without a high caloric intake.
Foods with a high volume to calories ratio are… Vegetables like beans and peas (including lentils).
Refilling your glycogen storage for hunger control and fat loss.
We’ve seen that a cause for a gnawing hunger sensation that ultimately gets the best of you is depleting glycogen storage in the liver. That directly causes secretion of ghrelin. There is only one way to deal with this. Take it for a while, then have a cheat day.
This is why I keep saying that you need an average daily calorie deficit. It doesn’t have to be the same every day. You can even exceed your calorie requirement on your cheat day, which leads to a liver refill that stops the hunger for a few more days of proper dieting.
The cheat day also resets the secretion of leptin, which replaces the sensation of hunger with one of satiety (satisfaction), and plays a part in lipolysis. What leptin does exactly for lipolysis is unknown, but it has been demonstrated by statistical studies that included measuring leptin levels on a panel of people undergoing a strict diet.
Leptin levels decrease with time, and the lower the leptin level gets, the slower lipolysis gets.
This means that the cheat day has two major benefits: resets the hunger counter and restores your ability to lose fat (just don’t forget the other lipolysis factors like water and oxygen).
Hunger’s alter-ego: satiety.
We’ve seen the causes for hunger: ghrelin and re-inforcement, a psychological state that you can partly overcome just knowing it exists. Now let’s take a look at the causes that counter hunger, creating the sensation of satisfaction that comes from a good meal: satiety.
We’ve already covered two causes for reduced hunger, but neither really has anything to do with satisfaction. Leptin is secreted by the fat cells (a strong argument against liposuccion). Leptin curbs hunger and plays an unknown chemical part in fat loss (well, I don’t know it, and neither do the sources I read). The opposite of re-inforcement, punishment, can psychologically erase hunger.
Cholecystokinin, an ally for fat loss.
A hormone called cholecystokinin is one of the causes of real post-meal satisfaction. It is secreted by the intestines, which means it doesn’t kick in right after eating (not until the food leaves the stomach). Cholecystokinin is important to know about because it is a very complex hormone that is made up of just about every amino acid that exists in the biological world (over 100). This includes the essential amino acids that you need to have daily in your diet (or as close to daily as possible).
This is what makes it important. It establishes a rule that you need to follow to be able to stick to your fat loss plan, and not fall off the wagon because of hunger. You need a source of essential amino acids (any animal protein) on a daily basis. Not necessarily much (the rest can come from vegetable proteins), but some. Without the essential amino acids that the body can neither store or synthesize, cholecystokinin cannot be synthesized. That is a powerful ally against hunger, and for fat loss that goes missing.
Another important fact about cholecystokinin is that it was discovered in 2002. This has nothing to do with the fat loss plan you are building, but is worth mentioning because this highlights an important fact: science is still far from knowing everything about how the body works. Spectacular discoveries have been made, but many more will probably see the day in coming years. The gene that causes the secretion of leptin was first isolated in 1994, uncovering a missing link scientists suspected existed since the early 70s.
Not exactly ancient history either.
Your stomach “knows” what it wants.
Hormones and psychology aren’t the only factors influencing hunger. Your nervous system claims a part in the complex mess as well.
There is a nerve that directly links the stomach to the brain called the vagus nerve. It sends signals that vary in intensity and frequency according to what is in the stomach. Each type of food detected there influences the signal.
Protein alone makes up 40% of the satisfaction potential caused by the vagus nerve. Another argument not to cut the protein, but carefully. You need your small intake of essential amino acids on a regular basis (as close to daily as possible), but the rest can come from vegetable protein. This allows you to ensure proper protein intake, and keep the calorie count under control.
Good sources of vegetable protein are… Beans, peas and lentils! What!? Them again?? Yup.