What if I told you that you could lose up to 200 lbs (90 kgs), without exercising, and without ever going hungry and while eating as much as you want? You’d say I was crazy right? Well, it turns out that a study published in a little-known journal in the 1960’s did exactly this (1). They took a number of obese patients and put them on a special diet that resulted in them losing staggering amounts of weight. They didn’t exercise and they ate as much as they wanted.

Sounds unbelievable I know, but there is a catch, and  you’re probably not going to like it. But stick with me as it will become clear why this is the case.

The researchers predicted that the reason we eat so much more food than we biologically need is not because we are gluttons, but because of how modern foods stimulate the brain. The idea is that the brain is hardwired to seek out foods that deliver the most pleasure to us, and so motivating us to hunt and gather those foods in favour of less pleasurable foods. This is known as the concept of “food reward”. This worked really well for hundreds of thousands of years, but recently with the advent of engineered foods, things have gone awry.

More on this later, let’s take a look at the study first:

The researchers at Colombia University designed an experiment that was designed to take away ALL stimuli to the brain that would cause the patients to overeat. They designed a feeding machine that dispensed a liquid formula to patients via an oral feeding tube (sounds tasty already right!). The patients simply had to put the tube in their mouth and press a button on the machine, and the machine would deliver a measured dose to the patient. By doing this, the researchers knew exactly how many calories the participants were consuming. The formula was designed to be pleasant, but not overly tasty. In designing the experiment this way, they could separate the effect of food reward on eating behaviour; because the experiment removed all the reward value from the diet, and reduced it to only the calories.

So what happened?

Well, first they put a normal weight person on the machine to see what would happen to his weight and calorie intake. He was instructed to consume as much as he wished, and to never go hungry. The trial lasted for 16 days and here is what happened:

As you can see from the graph above, his calorie intake varied a bit from day to day but ultimately hovered around the 3000 mark, his weight also remained stable throughout the 16 days, this is what they expected to happen. The patient was normal weight, so his brain was accurately determining how many calories he needed to maintain his weight by finely regulating his hunger levels. They did this on one more normal weight subject and the results were the same: calorie intake averaged out, and weight didn’t change.

So now the researchers wanted to know what would happen when they introduced obese subjects to this machine. Would their calorie intake stay the same like the normal weight subjects? What would happen to their weight?

The first subject to take part was a 27 year old man who weighed 400 pounds (180 kgs). As before, he was told to consume as much of the liquid food as he wished, and to never go hungry. The results were rather astonishing.

Now before we get to the results I should point out that before the patient was put on the machine, he spent a week in the hospital so they could get a baseline measure of how much he was eating on normal food. They determined that it was around 2,200 calories a day.

As soon as he was put on the machine, his intake immediately dropped to less than 275 calories a day. Now remember, he was told to eat as much as he wanted, so he wasn’t trying to eat less, he was just not hungry. He stayed on the feeding machine for a further 28 days; his weight loss at this point was around 45 pounds (20kgs)!

At this point, the researchers switched him to drinking the formula by cup rather than the machine. His calorie intake spontaneously increased from 275 to 500 calories per day. The researchers concluded that just the small increase in physical enjoyment from drinking from a cup rather than the machine was responsible for this increase in calorie intake. He was still running at a very significant calorie deficit, however, so his weight loss continued. He stayed in the hospital and ate this way for 70 days in total, at which point he was told to go home and consume only 400 calories of the formula per day. He did this happily.

After 8 months on this experiment, he had lost a staggering 200 pounds (90kgs)! This is without hunger, and without any additional exercise. He lost nearly a pound a day (1/2 kg). Below is the readout of his weight and calorie intake (excuse the poor quality, it was 1965 after all!). The top bar was his weight, you can see it consistently dropping. The bottom is his calorie intake. 

You can see that his calorie intake was normal when on the regular hospital diet (the first column), then it immediately dropped when he started feeding with the machine (second column). This was the first 70 days of the experiment.

The below graph is the rest of the experiment where he was allowed to go home on the same formula. His calorie intake was constant at 400 per day, and his weight loss continued until he had lost a total of 200 lbs (90 kgs). He never felt hungry and he never exercised more than normal.

Pretty amazing stuff right.

To make sure this wasn’t a freak case, they tested the same feeding machine on another patient, this time a 36 year old woman who weighed 390 pounds (175.5 kgs) . The results were just as staggering: she spontaneously reduced her intake to 144 calories per day, and lost 23 pounds (10.3 kgs)  in just 12 days. Three additional subjects showed similar effects from this experiment.

So this study sort to determine what would happen when all “reward” was taken out of the diet of an overweight person, and the results were spectacular. The brain was no longer being tricked by the engineered food that we so commonly eat today, and was able to accurately determine exactly how many calories it needed to consume. The results from the normal weight patients indicate that once all of the excess weight was lost, their calorie intake would stabilise and they would maintain a normal weight thereafter.

The reason that these people were able to live so happily on such a low calorie intake, was that their body was using their body fat as energy instead of the food they normally consume!

So why is this? What is going on?

Well to understand we need to take a closer look at what in our body regulates our body weight:

Your Brain Controls Your Weight

Like your blood pressure, temperature, heart and respiratory rate, your body weight is mostly controlled by your brain. To understand what makes us fat, we have to look at the part of the brain that drives us to eat and regulates our energy expenditure – the hypothalamus.

The hypothalamus is the part of the brain that has this important job. It does this by regulating food intake (hunger levels), energy expenditure (energy levels) and storage of fat tissue in the body. Under normal circumstances, the hypothalamus keeps your weight within a very narrow range (like blood pressure and heart rate). The system has been designed by evolution to ensure we stay at a stable body weight. It’s worked very well for millions of years, but something in the modern world – as we will see – has confused this system and is causing unwanted weight gain.

Your brain has a body weight set point; a specific weight that it tries to keep you at. Like a thermostat in your house, it works by keeping it in a specific range. The system “defends” a point of body weight. Notice how if you go on a diet, then off it again, you end up at more or less the same weight as before? Or how, with no thought at all, your weight remains stable over the space of weeks/months? It might creep up slowly over years but it remains pretty stable in the short term. This is because your brain changes your energy levels, hunger levels and the efficiency of your cells to keep your weight within a specific range.

The traditional way to lose weight is to drop calorie intake and increase energy expenditure. This is effective in the short term to lose a bit of weight. But what happens when you do this, is your brain picks up on this and puts you into “conservation” mode. It panics because it doesn’t know when the next meal is going to come from. So your brain makes you hungrier (to try to get you to eat more), more tired (to get you to expend fewer calories) and increases the efficiency of your cells when burning energy (to save calories). So because your brain “defends” your current weight, you get tired, hungry, and eventually give up because you’re effectively fighting your brain. Losing weight this way is exceedingly difficult, as you are doing the opposite of what your brain wants to do.

Now here comes the interesting part.

Say you wanted to gain a heap of weight, so you decide you are going to eat as much as you want (and more) for 3 weeks straight. The results obviously would be that you would gain a considerable amount of weight. What would happen when you go back to your normal way of eating? When you eat only when you are hungry. Your brain will do exactly what it did when you tried to lose weight; it would step in and try to return you to your “set” weight. So it would decrease your hunger levels (so you intake fewer calories), give you more energy (so you expend more calories), and make your cells less efficient at burning energy (so you use more calories). Through these changes, your weight would slowly drop and you would find yourself at more or less the weight you were before this experiment. This is a very well documented phenomenon (2)(3).

The problem we have now, with people who are overweight, is instead of defending a normal weight, the hypothalamus defends a higher body weight. So the brain’s system still works, it just thinks that the normal body weight is higher than it should be.

So to recap, your body weight is regulated by your brain (the hypothalamus), it has a specific “set point” that it keeps you at. So when it drops too low, your brain reacts by increasing hunger levels, decreasing energy levels and increasing the efficiency of your cells. When your weight gets too high, the opposite happens. This system works very well, however, the problem we have in the 21^st century is that the body weight set point is too high. Your brain has been tricked somehow into keeping your body weight at a much higher level than it should.

So what is it that is causing your brain to keep you at this higher level? The theory we will be discussing is called the food reward theory of obesity.

Food Reward and Obesity

To fully understand this theory, we will need to understand what makes us eat, what causes us to seek out the foods we eat, and what they have in common. We need to visit the brain again.

Evolution has put in place certain mechanisms in the brain to drive us to seek out rewarding and palatable foods. The idea is that we get pleasure from eating highly rewarding and palatable foods. Think about how much pleasure you get from eating a McDonalds’ meal or any “junk” food. Now compare this to eating a stick of celery. The former is the kind of pleasure that we are talking about. Your brain “rewards” you with good feelings when you consume these foods. This system is designed by evolution to reinforce and motivate you to seek out high-calorie foods. By doing this, you seek out these foods and consume them more often that you otherwise would. The result is that you maintain a higher calorie intake and therefore are more likely to survive in times when calories are harder to come by. This system, paired with the body weight “set point” historically kept your weight within a very narrow, healthy range.

So what does this system motivate us to eat? The answer is fat, sugar, salt, starch, calorie dense foods, certain flavours, textures and smells. Our brains are very sensitive to these food qualities because they are all elements of highly nutritious, calorie dense foods that would have sustained us 10,000+ years ago. So this worked great for millions of years, but recently this system has broken down. Elements like fat, sugar, starch and salt have traditionally been found alone, however with the advent of modern foods these ingredients have been combined and our taste buds and brain doesn’t know how to deal with it.

How Capitalism is Hurting Our Waists

So we know that certain food qualities reinforce our eating behaviour which results in us seeking out these foods instead of others. Enter capitalism and we have a perfect storm of manipulation that your brain simply cannot cope with.

Food manufacturers have discovered that the tastier the food is, the more people eat it (I know this is very obvious but stick with me), and so to get ahead of their competition they design foods to be more and more rewarding to this system in your brain. This drives more sales of their food. To make the highest rewarding foods possible, they hire food chemists; people who have the sole job of making their foods hit those pleasure centres as hard as they can. So you will come back again and again to eat their foods. They combine different flavours and textures with different combinations of fat, sugar, and salt to produce foods that we simply can’t say no to (4).

One of the most effective combinations is sugar and fat. Think about this: how much do you enjoy eating table sugar on its own? Probably not much. What about lard? Probably less so. How about white flour? Doesn’t sound very appetising, does it? Well when all of these ingredients are added together, you get a number of foods that most of us can’t resist: doughnuts, cakes, cookies, pastries etc. By simply combining these three ingredients we come up with a number of highly rewarding foods. This is just one example of how they engineer our foods. It’s gotten even worse with modern foods, however, with artificial flavours and flavour enhancers that number in their thousands.

Now your brain is still living in the pre-agricultural world, where the most rewarding food it encountered was some berries, honey on rare occasions or a fatty steak. What happens when your brain encounters these engineered foods; foods designed to hit it as hard as they can? The brain can’t cope, it gets overstimulated, and so it loses track of how many calories you should be consuming. The result is that you keep eating far longer than you otherwise need to. These calories need to go somewhere, and so you gain weight.

The more you consume these hyper-rewarding foods, the more your brain gets tricked into thinking it should consume more food than you need. So your brain ends up “defending” a higher weight. This is the main factor that is driving the obesity epidemic. And it’s only going to get worse.

So this explains why the participants in the above study lost so much weight. Their brains were used to living on highly palatable foods that have been literally designed to cause overeating. Their brains then go cold turkey on all of this highly rewarding food, they’ve been given a rest and the brain can finally do it’s job properly. It’s no longer being hyper-stimulated. It’s no longer being hypnotised.

So when the brain snaps out of this trance that these foods have put it in, it thinks “oh shit, this body of mine has a lot more weight than it needs”, and so it cuts your hunger signals so much that you barely eat. The result is that you end up living off your excess fat reserves until you reach normal weight. Your calorie intake would return to normal then.

So how do we make use of this information to lose weight? I hear you say.

Well, there is a solution, but you’re not going to like it.

You need to cut out all processed and packaged food. Anything with more than 3 ingredients is off the list. No soda’s, no fast food, no donuts, no KFC. Nothing similar to those.

Yep, I told you you wouldn’t like it.