If you choose to go on a diet.. I wantto show you the results of a study that is basically the best medical sciencecan do. This is The Look AHEAD Study and they took more than 5,000 people who were diabetic and either overweight, or obese,and put them on an incredibly intensive diet with an unbelievable amount ofsupport. They had group classes. They had individual consults. They had physicalactivity specialists. They had nutritionists. They had psychologists.They specifically identified individual barriers to weight loss and strategizedwith people for how to overcome it. They had over 300 contacts each withprofessionals over the 10 years of this.
Study. And at the end of it the average person in the intensive diet group had lost 5.7pounds more than the average person in the control group. About a quarter ofthem had lost 10% of their body weight and kept it off which is the goldstandard in modern medicine for diets. And just about exactly the same numberhad gained weight and the rest of the were pretty much where they'd been tobegin with. So this is the best we've got and it's pretty underwhelming, at least in my opinion. So why is it so hard to keepweight off? The answer to that is not in yourstomach but in your brain.
I'd like to introduce you to thearcuate nucleus of the hypothalamus which basically serves as a thermostat toregulate weight. And so you know what happens with your house's thermostat ifyou leave the setting alone and you decide that you want tocool the house down by opening a window say in the winter. Anybody who's everlived in a New York apartment where the landlord doesn't allow you to controlthe setting for the heat might be familiar with this processalready but what typically happens is that the place cools off for a while andthen heater kicks on because the thermostat says to itself this place isnot at the correct temperature. We better.
Pour some more heat in. Something very,very similar happens in your brain when you lose weight. Everybody has a, what's popularly called a set point, scientists call it the defended range,because that's a little more accurate. It's for most people somewhere in thevicinity of a range of 10 to 15 lbs where your body is comfortable. And if you get above that your body will try to get you, your brainwill try to get you back down for a while, kind of half-heartedly. If you get below thatrange though your brain will try to get you back up toit, intensely and relentlessly.
And that is the solutionthat evolution put together over hundreds of thousands, or millions ofyears. You know, every mammal has this mechanism to solve a problem that we nolonger have: the ever present scarcity offood. Because if you think about it in, you know, in a hunter gatherer tribe forexample, your odds of weighing 500 pounds are pretty slim. On the other hand your odds ofstarving to death are not negligible. And so your brain puts a lotmore energy into making sure that you're not starving todeath. And unfortunately it doesn't.
Really seem to take into account whereyou're starting from in that process. For most people, you know, youyou probably know what weight it is that you can maintaincomfortably, what weight it is that you always go back to after you've been on adiet. If you've had that experience that is probably your defendedrange. So when you, how does the brain do this? Basically this is the master controller that changes a whole bunch ofphysiological factors. You don't have to memorize this, there won't be a quiz, butyou can see that this is, this is controlling a bunch of hormone andneurotransmitter systems that basically.
Have two major aims: increase energystorage, which is to say reduce the amount of energy that you burn, andparticularly it turns out reduce the amount of energy that you burn throughphysical activity, now that's great if you're a hunter gatherer who's havingtrouble finding food, you, you actually become a Prius and you get more miles pergallon from the food, so that you can go farther, looking for more. It's not sogreat if you're going to the gym trying to burn 500 calories. And then the other effect is to increase your appetite and increase foodintake. And some recent work has actually suggested that that effect is largerthan the effect on metabolism. So.
Everybody likes to think about themetabolism because it really feels like something you couldn't possibly help,it's definitely not your fault. But people eat more withouteven realizing it, too, and sometimes quite a lot more. Dieting has a varietyof psychological effects that are not good for you also. I already mentionedthe tendency to become fatter but also there's a strong risk especiallywith repeated dieting for the development of eating disorders including bingeeating which is probably at least some of the mechanism behind the weight gainthat I mentioned. And the other thing that's kind of more subtle but reallyinteresting to me is that when you diet.
You are teaching yourself to eataccording to rules. You're teaching yourself to eat according to somebody else's plan. And people who do that get out oftouch with their bodies. They have trouble telling when they're hungry andif you have trouble telling when you're hungry you're going to have troubletelling when you're full. They frequently eat when they'renot hungry. They eat for emotional reasons. They eat for social reasons. Theyeat just because somebody puts some food on the table in front of them. So these,these are the typical psychological characteristics of frequentdieters and it all comes back to.
The idea that somebody else should betelling you what to eat. So I want to show you one more studyreal quick. This was an epidemiology study that asked people about fourhealthy habits: did they eat five servings of fruits and vegetables a day?did they exercise at least three times a week? did they not smoke? did they drinkless than two glasses of alcohol per day? And normal weight you can seebasically that the more healthy habits people had the better off they were interms of their risk of death. Same thing in the overweight group.Same thing in the obese group. But here it becomes very clear that the problemis not obesity itself but the.
Correlation of obesity with badlifestyle habits. Because if you look just at the people with four healthyhabits there's no difference based on weight. So these are the facts. These are thehabits and I want to close with a quote from a doctor of Public Health atHarvard who has been really famous for insisting that everybody needs to loseweight and even headmits that you can substantially decrease your risk of death and improveyour health by adopting healthy.
Lifestyle habits. So my basic position,you know, you these are I'll I'll give you the facts you can do what you wantwith them. My personal interpretation is that we should, we'regrabbing this problem completely by the wrong end. We're insisting that everybodyhas to do the very hardest thing that helps the least. Okay? Does that make any sense? How about we start by getting everybodyto exercise for half an hour a day before we even begin to ask them howwhat they weigh. How about we get people to eat some more vegetables before weask them what they weigh. How about we.
Take hold of this problem from the endthat we can do something about. You know, there's nothing in your brainfighting against you going for walk for half an hour. And if there is youonly have to fight it for half an hour. Right? If you're on a diet you haveto fight it 24 hours a day. All right, so that's my pitch. That'swhy you should never go on a diet.