Controlling Hunger-Part 1

Dr. Jason Fung

Note: Written with Megan Ramos of Intensive Dietary Management Program.

Have you eaten a loaf of garlic bread, a bowl of pasta, and a dish of pistachio gelato and still felt hungry? Have you come home from dinner and then ate a bag of popcorn in secret to satiate you before bed? You’re not alone. I hear these stories from people every day, and I’ve had some of my own. Your mind is telling you that you are full because you must undo the top notch on your belt, but your stomach is still complaining it’s empty. Some people continue to eat, sometimes all day long, until mere moments before they go to bed. They feel helpless and out of control, binging on foods they know they should be avoiding.

Then everybody knows people who are the complete opposite. Those people who eat half a sandwich or a small salad at lunchtime and then declare themselves completely stuffed. And they’re not trying to be modest. They are actually completely full. They won’t eat more because it is uncomfortable for them to do so. These people are often quite thin.

Many of our IDM Programclients have undergone bariatric surgery. Their appetites were so far out of control that they felt they needed invasive, expensive surgery to regulate their unruly bodies. And despite all the promises of bariatric surgery to allow patients to lose weight and improve health, it fails almost invariably. The stories are eerily similar. Initially, they lose some weight, but after several months the weight creeps back on. But worse, they feel that their appetite is just as out of control as it has ever been. “How can this be?” they ask despairingly. “I’ve had my stomach physically stapled to make it smaller!”

They misunderstood the problem with hunger. It’s not about the size of your stomach. Hunger does not occur because your stomach is too big. And if that is not the problem, then surgically cutting it smaller is not going to help. Likewise, hunger is not about your willpower or self-control. You cannot will yourself not to be hungry. You cannot ‘decide’ to be less hungry. You are hungry or you are not. Your appetite is hormonally driven. That is what we need to fix. Not surgically rewiring our intestines. Not counting calories. If you don’t regulate your appetite on a hormonal level, you’ll never regain control no matter how small your stomach is.

We are hormonally drive to eat (we get hungry) or to not eat (we get full). If people are given dietary advice that makes them hungrier, then they’ll eat more. That’s not their fault, that’s normal. What advice have been the cornerstone of dietary therapy for weight loss for the last 50 years? Cut a few calories each and every day by eating low fat foods, because fat is very calorically dense. We are also told to eat 6 or 7 times per day, or ‘graze’ rather than eating 3 main meals per day as all our ancestors used to do. Sounds pretty reasonable. Here’s why it doesn’t work at all.

There are certain hormones that make us full. These are called satiety hormones, and they are really very powerful. People often imagine that we eat just because food is in front of us, like some mindless eating machine. That’s far from the truth. Imagine that you have just eaten a huge 20-ounce steak. It was so delicious, you even ate a few extra slices, but now you’re completely stuffed. The mere thought of eating more nauseates you. If somebody set down another 12-ounce steak and offered to give you everything for free, could you do it? Hardly.

Our body releases powerful satiety hormones to tell us when to stop eating. And once these kick in, it’s extremely difficult to eat more. This is why there have always been restaurants that will offer you a free meal if you can eat a 40-ounce steak in one sitting. They aren’t giving away very many free meals.

The main satiety hormones are peptide YY, which responds primarily to protein and cholecystokinin, which responds primarily to dietary fat. The stomach also contains stretch receptors. If the stomach is stretched beyond its capacity, it will signal satiety and tell us to stop eating.

So how does the low-fat, calorie reduced diet eating 6 or 7 times per day stack up? By cutting out the fat, we don’t activate the satiety hormone cholecystokinin. Because protein is often eaten along with fat (like a steak, or an egg) then you are not activating the satiety signal peptide YY. This makes us hungry. So, a few hours we eat, we get hungry again. So instead of waiting until the next meal, we eat a snack. Because snacks need to be easily accessible, it tends to be carbohydrate based, like a cracker or a cookie.

It’s fairly simple to prove to yourself. Think about eating steak and eggs for breakfast, which is high in dietary fat and protein. Do you imagine that you would get hungry at 10:30? Now imagine that you ate two slices of low-fat white toast with low fat strawberry jam, and a big glass of orange juice. There’s virtually no fat or protein in this breakfast of champions, but you know as well as I that we are ravenous by 10:30, which sends us out on a mission to find a low-fat muffin to tide us over until 12:00.

Now, instead of eating 3 larger meals, we are eating 6 or 7 smaller meals, this means that we are not activating the stomach stretch receptors to tell us that we are full and should stop eating. While cutting our stomachs to a smaller size with bariatric surgery may seem like an option, the nerves that supply the stomach are often cut during this time, so they cannot provide those all-important satiety signals

The standard dietary advice to lose weight was doing everything exactly wrong. It could hardly have been worse if they were trying. But it wasn’t a problem with the number of calories. The problem was that the diet we were told to eat for the last 50 years did NOTHING TO CONTROL HUNGER. The problem is not with the people, the problem is the advice nutritional authorities are giving to the people.

The problem is amplified if we are eating, as most people are, processed and refined carbohydrates. Your blood sugar levels skyrocket telling your pancreas to produce a surge of insulin. The job of insulin is to tell your body to store food energy as sugar (glycogen in the liver) or body fat. That huge spike in insulin immediately diverts most of the incoming food energy (calories) into storage forms (body fat). This leaves relatively little food energy for metabolism. Your muscles, liver, and brain are still crying out for glucose for energy. So you get hungry despite the fact that you’ve just eaten. It’s the domino effect from hell if you’re looking to maintain or lose weight. Because these processed foods have removed all or most of the fiber, it does not take up much space, and does not activate the stomach’s stretch receptors. Because they are low fat, they’re removed most of the protein and fat. So, there’s no activation of the satiety signals, at a time when most of the ingested calories of food energy have been deposited in the body fat. No wonder we get hungry! After a huge meal, we can often find ‘room’ for dessert, which is usually highly refined carbohydrates, or we can still drink that sugar sweetened beverage.

For years you’ve been lied to. You’ve been told that you lack the will power and that your obesity is your fault. That couldn’t be further from the truth. You think your body is broken because your body doesn’t respond the way you’ve been told it is supposed to. You know you’re following the rules. You’re eating what the authorities tell you to eat. You’re barely eating at all to keep your caloric intake low. You can’t lose weight and you’re hungry all the time. With about 70% of Americans overweight, is it possible that 70% of Americans are broken?

Eliminating processed junk foods and using intermittent fasting regulates the hormones that control your appetite. People tell me all the time how they turned down bread or cake for the first time ever because they just didn’t feel hungry. So, reducing refined carbohydrates and enjoying natural fats and proteins can create long lasting satiety. But how can you further reduce hunger? The answer, counter-intuitively, is fasting. Eat nothing can shrink your appetite.

A young doctor at theIDM Programhad struggled with his weight for many years but eventually lost some weight with a low carbohydrate diet. He wasn’t at his ideal weight, but he was happy to finally be experiencing some weight loss. But he felt like a slave to food.

After spending the week with me and seeing all the ways fasting can benefit the dozens of patients, he was motivated to try a 7 day fast. He started his fast without much difficulty, but he was nervous knowing his problem with hunger. When I followed up with him, he said “for the first time in my life I turned down food because I just didn’t want it. It wasn’t that I was abstaining because I was fasting, I just really wasn’t hungry. Megan, I’ve never turned down food like that before.”

Many people are frightened to fast because they think it will only increase their already out of control hunger. We’ve had experience working with thousands of patients adding intermittent fasting to their daily routine. One of the most consistent comments after they start fasting, is how much their appetite has gone down. They always say, “I think my stomach shrank”. They often report feeling full by eating only eating half the amount of food that they used to. No, their stomach didn’t physically shrink, but their appetites sure did.

The hormone ghrelin is also called the ‘hunger hormone’ because it turns on our appetites, so you’re want to lower it. People assume that if you’re fasting, your ghrelin level is going to continue to rise, but that isn’t true. And most of you know this by now because you’ve been hungry for years. Eating all the time does not turn off hunger and lower ghrelin. The answer to turning down ghrelin is the opposite — fasting.

Hormones are cyclical, meaning they go up and down throughout the day. Circadian rhythm studies consistently find that ghrelin is typically the lowest first thing in the morning. Patients are often not hungry in the morning but they eat because they’re told it’s “the most important meal of the day”. Ghrelin also fluctuates throughout the day, which is why we tend to experience hunger in waves throughout the day. If you are able to fast through the wave, you’ll find yourself no longer experiencing the desire to eat a couple of hours later. Research shows that over the entire day of fasting, ghrelin stays stable. Not eating for 36 hours does not make people more or less hungry than when they started the fast. Whether you eat or don’t, your hunger will be the same. Why? Because if you don’t eat, your body will simply take the food energy (calories) it needs from your stores (body fat). You are, in essence, letting your body ‘eat’ your own body fat. Perfect! Once you open up those stores of body fat, you are not hungry, because your organs have access to all the its energy needs.

Ghrelin is also observed to gradually decrease after three days of fasting. This means that people are less hungry despite not having eaten for 72 hours! And we hear this from our patients every day. Hunger is a hormonally mediated state of mind, not a state of stomach.

What’s even more interesting is that there a greater decline in ghrelin secretion in women than there is in our male counterparts. This indicates that women can expect to have more benefit from fasting because their hunger can be expected to decrease better than men.

Most of the complications associated with fasting are mind over matter. People think they’re going to be starving and it’s just impossible. I understand because at that point their eating all day long and feeling like they’re hungry from sunrise to sunset. This is why I encourage people to just rip off the band-aid and try to do a 24 or 36 hour fast.

“Just try it once,” I tell them. “If it’s that bad, then we don’t have to do it again.”

Never has anyone stopped after one fast. They’re surprised at just how easy it was and how satiated they feel. Fasting can give you control back.

Dr. Jason Fung

Written by

Nephrologist. Special interest in type 2 diabetes reversal and intermittent fasting. Founder of Intensive Dietary Management Program.

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