Starvation mode, does it end?

milleniahexe wrote: »

I am on phentermine and i was told by the doctor that if i eat less than minimum necessary calorie intake (for me its about 1200), my body will go into starvation mode and weight loss will slow down. I often eat less than that, but my theory is that even if starvation mode occurs it cant last forever and eventually the body will have to dig in into the ample yummy fat reserves! What is your take on it? I have never heard of a person who for whatever reason has been forced to eat few calories for weeks or months to emerge with the same weight as before so the mode has to stop after some time! I read here that muscles get used up before fat but what if i am using my muscles in regular exercise? That further lowers my calorie intake. According to starvation mode, id stay fat forever or even put weight on, and that doesnt make any sense. If less is coming in than going out, weight has to go!

savithny wrote: »

Well, the origination of the idea of "Starvation mode" is often cited as the Minnesota Starvation Experiments of 1944-45.

https://en.wikipedia.org/wiki/Minnesota_Starvation_Experiment
http://www.bbc.com/news/magazine-25782294

I'd point out that:
1) This was a carefully controlled experiment that started with normal-weight volunteers.
2) "Starvation" was defined as a 1000 kcal/day deficit, more or less. The object was for the men participating to lose 25% of their body weight, which was "normal" at the start of the experiment. They were "starved" on between 1500 and 1800 calories a day.
3) The period of starvation lasted 24 weeks.
4) participants experienced "marked declines in physiological processes indicative of decreases in each subject's basal metabolic rate (the energy required by the body in a state of rest), reflected in reduced body temperature, respiration and heart rate." They also experienced some fairly serious psychological symptoms, including depression and anxiety.
5) They experimented with different forms of re-feeding afterwards, but it took months to years for some men's health to return to normal.

The objection that "if starvation mode existed, no one would starve to death" ignores the fact that for most people experiencing famine, they're surviving on significantly *less* food than they need, not on NO food. What "starvation mode" means is that you become able to live and maintain on a lower amount than you would have previously, as your body defends its mass by slowing everything down. Yes, if you stop eating entirely, you'll die eventually. "Starvation mode" makes it take longer. "Starvation mode" means that if you get put in prison and given 1000 calories a day, you'll lose weight to the point where CI=CO again -- and that point may not be what the calculators on sites like this would predict.

Multiple studies since 1945 have documented that drastically lowering intake results in significant lowering of metabolic rate, and you don't have to be "starving" to experience it. How many people here are aiming for 1500-1800 calories a day? How many people here are trying to create a deficit of 1000 calories per day? Everyone aiming for 2 pounds a week of loss is creating as big a deficit as these men were.