At 31:20 minute of the video Dr Lustig repeats his usual 'soda before meal' scenario. Note it is not a 'fructose before meal' scenario. It is sugar on virtually empty stomach and then the child eats more than if it received nothing or just water. How is that possible?
You hear him saying that the brain did not notice those 150 kcal of energy. Why is that?
You could hear before that glucose stimulates satiety receptors in the brain while fructose does not and that was the reason why people consumed more food. Let me just remind you that the sugar is consisting of: 50% fructose and 50% glucose.
Now, try to answer my question: why the brain did not notice the 75 kcal of glucose energy that drove insulin levels up? Not mentioning that about half of fructose is also converted to glucose in the liver, especially when not in a fed state, which was exactly this scenario. Another reminder: in a fasted state, a large portion of consumed carbohydrate, especially glucose, is converted to glycogen since its stores are depleted after overnight fast. If there was only several hours gap between the meals, this is not the case. So, depending on the length of time between two meals, the insulin response to carbohydrate will be different. But let's say, the hours were only few and after consumption of soda drink there was an adequate insulin response in the body.
What do we have the insulin for? The body synthesizes the insulin to enable glucose entering the insulin mediated transport proteins and metabolic pathways so that the glucose concentration in the blood can be maintained at narrowly regulated levels. Higher levels cause the damage of various tissues while low levels cause fatigue or even a diabetic coma, sometimes leading to death.
Now let's put all these things together: at least 75 kcal of glucose triggered early release of insulin because from the sweetened drinks we get the sugars into the blood quite quickly. The insulin cleared up the glucose from the blood stream, reducing the blood glucose to probably even a lower level than it was before drinking the beverage. Are you surprised that the child felt hungrier when it entered the fast food outlet and got the food in front of it? This is exactly the mechanism and the reason why the carbohydrate rich diet based on processed carbs (with a high glycaemic index) makes people fail at weight loss - their spikes in blood glucose followed by spikes of insulin make them like on a metabolic roller-coaster with repeated hunger pangs during the day. And this applies not only on sugar but also on starch.
IT IS THE GLUCOSE then, not fructose.
The blame to be put on fructose is only in that it makes food sweeter and more appealing on our taste buds, especially when it is accompanied with fat and salt on top of it as are the notoriously known high fat, sugar and salt (HFSS) foods. The studies have demonstrated that people consume significantly more food when containing these three substances in the right amounts then if the food was less processed. Food industry, for the sake of profits, has put a huge effort in designing such desirable food products that make people eating too much of it and to buy it again.
Yes, Dr Lustig also mentioned the hormone ghrelin, saying that glucose brings this hunger hormone down whereas fructose does not. Did he forget what he said a minute ago - what the drink was sweetened with? SUGAR, not fructose or glucose only. Why the at least 75 kcal of sugar did not suppress the ghrelin? I think he mismatched two different kinds of studies of which some examined the effect of pure fructose on further food food intake and compared to pure glucose, and when listening further he actually referred to these studies. In that case yes, the data show this effect: fructose does not suppress a hunger hormone ghrelin. But the drinks were sweetened with SUGAR - half fructose and half glucose. Why the glucose did not suppress the hunger?
Maybe it did for a while, until the insulin did its job, making the hunger even worse afterwards. Did they measure that? I do not think so.
Hence this is just another example of manipulating the minds of people who do not have a sufficient knowledge to question such claims. Wake up!
No comments:
Post a Comment