Today I would like to share with you this lecture by Dr David Ludwig. In it he explains the difference between the calories in v calories out model and a diet that controls insulin. It is very much like we have spoken about many times in our writings and a lot of what we explain to our clients.
I like at the beginning where Dr Ludwig explains how as people started following the food pyramid guidelines and started following a low fat diet, the obesity epidemic actually exploded. In studies the high fat-low carb type diets actually work better at losing weight than the conventional caloric restriction approach and that the caloric restriction model is not a good way as keeping weight off long term.
"The body weight is controlled more by biology then will power over the long term". Dr Ludwig explains the primal mechanisms that are in built that help us control body weight. If we restrict calories and have strong enough will power to restrict calories long enough our bodies fight back in other ways, like slowing metabolism. So the combination of rising hunger, the slowing of the metabolism, and stress hormone secretion is a recipe for failure when trying to lose weight.
The opposite is also true. If you over-feed people, they lose all interest in food. They lose attraction to those foods and actually feel just as bad as the people in the starvation studies. Their metabolisms speed up trying to shed the extra calories and once the protocol ends their weight comes back down to where it started.
This is why planned re-feeds are an important part of any fat loss plan.
This suggests we have a body-weight set point but Dr Ludwig asks the question "why then has this set-point increased over the years?" He explains that we are storing more calories in the fat cells, and that the body only looks at the calories available in the blood. So we actually have to few calories in the blood, the fat cells are on a feeding frenzy, and the rest of our bodies are actually starving. The brain only sees the amount of calories in the blood to fuel metabolism, not the calories in the fat cells, and this is why we get hungry and why our metabolism slows down as we are trying to conserve energy, thinking we are in a famine. This is why you get tired on a low caloric diet, you are trying to conserve energy.
What is triggering our fat cells to over store calories?
Insulin. He uses an example of a child with type 1 diabetes, who can't make insulin, will come to attention due to weight loss no matter how many extra calories that child eats, even 5-10,000 calories more. When given the right amount of insulin the child's body weight will return to normal, give him too much insulin and he will predictably gain more weight.
What drives the insulin secretion?
Excessive carbohydrates, mostly processed carbohydrates and carbohydrates that spike the blood sugar rapidly, like we have said many times before. Insulin is a storage hormone so when it is spiked very high after a meal, if you are insulin resistant, a lot of the calories eaten will be pushed into the fat cells. Adrenaline also rises after a meal that causes a high amount of insulin to be secreted. After a high sugar breakfast subjects selected 600-700 calories more throughout the day.
What is the impact on the brain?
The fast carb type meals trigger a part of the brain, that deals with rewards and cravings, and is seen to be triggered in many addictions like cocaine addiction, even 4 hours after the meal. So if you are hungry and this part of the brain is triggered you are going to perceive junk foods to be much more tasty then they actually are. If you eat excessive amount of a food, you no longer think it tastes as good as it did before you were full. Just the same, if you haven't eaten for a whole day, whatever food you do eat tastes great. So it isn't so much the taste of the food that we are addicted to.
The good news is when you stop eating these foods it doesn't take long for you to stop craving them. They lose the power of controlling our basic neurological responses as Dr Ludwig points out.
Fast carbs vs slow carbs
Dr Ludwig shows the results of a rat study that were quite interesting. They took rats and put them on either a fast carb or slow carb diet for 16 weeks, which is about 10 rat years he says. They tried to keep the weight of the rats the same in both groups. To do this, in the fast carb group they had to restrict calories to achieve this and the fast carb group also had 70% more fat mass. The fast carb group also had very high risk factors for diabetes and heart disease.
This is more evidence that if you eat quality foods and control your blood sugar, you are able to eat more and still maintain your ideal body weight. This is why many of our fat loss clients actually say they can't eat all the food we give them.
A study done on humans, which Dr Ludwig discusses in the video, also showed that on a low-fat, low-calorie diet, the metabolism dropped by about 400 calories per day but on the high- fat, slow-carb diet this didn't happen.
In conclusion
If you want to lose weight, maintain your weight, or be as healthy as you can be, then it is important to control your insulin levels. We talk about this all the time so I think the video is a good explanation of why you should do this and it comes from a doctor not just a strength coach.
Calories are not the whole story. Whilst they do play a role, it is only up to a certain point. The types of foods you eat are far more important.
This video talks about one aspect of how to lose weight but there are many more such as sleep and gut health and the make up of your gut microbiome for example . Controlling insulin is a very important point, especially in today's society as we tend to eat excessive amounts of processed carbs.