Its nothing complex, its simple actually. Body senses food shortage = adapts to environment by increasing fat storage to cope with future uncertainty. Thats what biology does you know. It ADAPTS. I think they call it evolution.
Literally every animal study ive seen shows weight regain and weight rebound after a period of calorie restriction. If the calorie restriction is severe it will force temporary decreases in fat mass while the calorie restriction persists, thats just more physics than biology. However many people pretending to be intelligent will think that is how to treat obesity.
Ofcourse calorie restriction is really incretin restriction. Thats whats really going on. As I have said many times, the incretin affect is the only way your body is able to determine current food availability in the environment. Leptin has a similar role, it tells the body about current reserves of fat stores that are already in the body. In a normal human the incretin response is suppose to be directly proprtional to calories ingested, however as we have seen it is broken in both situations of very low adiposity and high adiposity. In anorexia, the incretin response is over-exaggerated while in obesity the incretrin response is depressed.
As we know Roux-en-Y gastric bypass (RYGB) is one of the most effective "treatments" for obesity as far as producing weight loss goes, and there is considerable evidence to suggest it is only affective because it goes some way to restoring the incretin response. Up to 20% of patients cannot sustain their weight loss beyond 2 to 3 years after RYGB surgery. Weight regain-promoting consequences are attributed to a failure to sustain elevated plasma PYY concentrations ( 1 )
So sad, so depressing. So many people believing this; so many people trying to starve themselves (or telling others that they are lazy glutons)and so many people beating themselves up for not being able to starve themselves enough to lose the weight.
ReplyDeleteI don't think the issue is calorie restriction per se as it is fat loss in general; if the diet reverts to one facilitative of weight restoration (which it usually will) the person's weight will be higher than it was before attempting to reduce it. I believe this is caused by the cortisol/leptin dynamics induced by weight loss, where leptin is reduced excessively and cortisol is disinhibited / elevated, and new fat tissue will grow when insulin comes to the party.
ReplyDeleteAlthough, this may be a phenomenon found only in obese people because experimental studies in normal obesity resistant people usually show that the weight gain increase after refeeding is temporary, and they will revert to their prior weight once food intake is stable and sufficient.
I would expect low carb type diets to be even worse, if for no other reason that they are so effective to reduce body fat and insulin and leptin, that the rebound weight gain and metabolic consequences are that much more severe (as the deviation from baseline fat mass is also more extreme).
From what I observe most GBS patients start to regain after 2 years.
but eating a high-fat-moderate-protein diet is "accidentally" calorie-restrictive -- i'm not sure how to reconcile this.
ReplyDelete...unless one should say it DOESN'T restrict calories, because body-fat and endogenous glucose make up for what is missing in the diet....
DeleteThat is right Tess, calorie restriction at the mouth is NOT calorie restriction at the cellular level. For example your brain has no idea where the glucose molecules in your blood come from, it has no idea if the glucose molecules came from a potato you ate 2 hours ago or if it came from hepatic gluconeogensis 5 minutes ago.
DeleteRegardless of how little you eat, your brain always sees "adequate" glucose floating past in the blood.
The best example of this is again the RYGB patients, observantly they are starving because we see them eat 300 calories per day yet their body *thinks* otherwise because RYGB causes dramatic incretin secretion.
high-fat-moderate-protein ( low-carb ) most likely increases incretin secretion similar to how I posted before that glp-1 is higher with fat alone than with fat + potato. What im trying to say is that calories at the mouth is irrelevant, only the incretin response in the gastric system counts.
With respect to the mouse calorie restriction study above, I think theres likely more going on than incretins though, probably stress induced fat gain, if your constantly finishing your plate but still feeling very slightly peckish, it probably sends off a nasty stress signal to the body.
Calorie restriction with insulin chronically high does pose problems however. If nibbling on HCLF all day spikes blood sugar too high the protective hormones are not able to stop the body from feeding off the precious aminos of muscle and even organs. I know I did this back in my 20s when I fasted on juices for weeks. I lost very little body fat and felt so sick. Talk about autophagy with a twist!
ReplyDelete