What happens to your body if you don't eat enough calories?

It's not just about eating enough calories, but eating the right types of foods. You could eat 2000 calories of chocolate candy each day and some parts of your body would starve.

Starvation isn't just about energy -- it's also about nutrition. You have to have the right stuff with your calories to nourish your body.

Can I share my two cents worth?
I was eating under my calories (1200 cal) about 1000, and I can not say for sure if this is related to it or not, however, something has affected the heart. I started having irregular heart beats, in fact the heart was beating at 44 beats a minute and then would go faster. I am in a yo-yo effect and it seems like your energy is just being sucked out of you. I was okay as long as I laid still but as soon as I stood up then the blood pressure would drop. I ended up spending 9 days in the hospital while they tried to get it regulated. Is it "starvation mode?" I am not sure however, the doctor did suggest that I take 50 mg of magnesium to try to heal the heart muscle. I am totally exhausted and she figures it has thrown me into a full blown fibromyalgia episode and it could be months before I come out of it. So my recommendation is if you are going to go under your calorie level, then make your calorie level more realistic by setting it higher. I am now set for 1500, but I am still finding it hard to eat 1300. I am one of the ones who always praised those on MFP for staying under their calorie goals, but now I am going to stop doing that. )

Can I share my two cents worth?
I was eating under my calories (1200 cal) about 1000, and I can not say for sure if this is related to it or not, however, something has affected the heart. I started having irregular heart beats, in fact the heart was beating at 44 beats a minute and then would go faster. I am in a yo-yo effect and it seems like your energy is just being sucked out of you. I was okay as long as I laid still but as soon as I stood up then the blood pressure would drop. I ended up spending 9 days in the hospital while they tried to get it regulated. Is it "starvation mode?" I am not sure however, the doctor did suggest that I take 50 mg of magnesium to try to heal the heart muscle. I am totally exhausted and she figures it has thrown me into a full blown fibromyalgia episode and it could be months before I come out of it. So my recommendation is if you are going to go under your calorie level, then make your calorie level more realistic by setting it higher. I am now set for 1500, but I am still finding it hard to eat 1300. I am one of the ones who always praised those on MFP for staying under their calorie goals, but now I am going to stop doing that. )

What you are describing happened to you does not sound like starvation. Real starvation is not all that common in 1st world countries.
Your blood pressure dropping and your heart rate increasing is a positive sign of relative dehydration. You possibly did not have enough fluid (read this as blood and plasma) circulating in your vascular system. It's fine when you are lying down, because your heart doesn't have to pump as hard or against gravity to your upper half. When you stand, what blood volume you have "sloshes" into your lower body and legs; following gravity, thereby decreasing your blood pressure in your head and causing your heart rate to increase in response to this drop in pressure. Magnesium is an important part of muscle contraction, it helps the muscles (heart) to relax and recharge for the next contraction. Also there are a number of other things that can make the heart change it's speeds and beat erratically, I'm betting they performed lots of tests on you in the hospital to rule electrical disturbances and such out? Anyway, it is important to maintain proper nutritional balance in our intake, but it is every bit as important to stay well hydrated.
Good luck to you on your journey, you can do it!!

The headaches are true fact or maybe from too much exercise. I've noticed lately my heart feels a little irregular, but also might just be from the exercise. I had to quit a few years ago because I overworked myself and got sick from it. I'm thinking about eating back all my exercise calories, but it's so hard going back to eating normal at least right now.

Here is what I found out...

Answer:
you get really bad headaches! but other than that I guess you can lose weight.
First your body burns all of its stored energy, in other words, your excess fat. Then it begins burning your muscles, and you get weak and lose all muscle tone. You get hair on your back even if you are a girl, and the hair on your head is not shiny anymore, but thin and ratty.

If your body starts burning muscle, remember that your heart is a muscle, and your health is *greatly* at risk. If you don't eat enough calories, you eventually die.

- just a few questions to the original poster please:

Headaches I can go with.

Your second point - so it's ok for me to keep losing weight until I lose all my stored energy, in other words my excess fat, and I can stop just as I get to where I have just muscles and a small percentage of fat - or does the body burn energy stored in the muscles as glycogen, energy stored in the body as fat and also muscle tissue at the same time and in differing proportions?

Your third point regarding back hair - is this not just hereditary or will the back hair that I have had since puberty just disappear as I lose my excess fat? It hasn't started to happen yet but I do have another 20lbs to go I think.

I'm not saying you are wrong but I m a bit sceptical and a touch intrigued as to where you found your research material.

1st. As long as you do some type of weight training with cardio and eating less you shouldn't be losing muscle mass. Even with cardio you probably shouldn't eat into your muscles. Your glycogen storage is used up first then fat is used up. You have to reallllly under eat to cause muscle wasting. Been there done that, didn't seem like a problem at the time, it definitely was later.

2nd. Lanugo can develop in malnourished individuals it's fairly common in patients with anorexia nervosa, where it grows is hereditary, you also get it there from just aging. Hair is from an increase in testosterone production generally, so there is probably another underlying condition at play, but hair on the back isn't male pattern so idk.

bump

thanks for that it helps a lot...i want results but i want to do it properly...also what is a decent amount to burn per day by exercise..cheers for the help

I used to think that 1200 was the magic number... for about a week or 2... but then I realized that this would never work. I kept overeating on days when I was super hungry and ate anything I saw These days if I eat less than 1500 I get signs that my body isn't getting enough.. I am losing weight on 1600-1900 a day

Every time this thread comes up I read it "what happens to your body when.... "
and then I think

"you die"

but someone already said It LOL

I used to think that 1200 was the magic number... for about a week or 2... but then I realized that this would never work. I kept overeating on days when I was super hungry and ate anything I saw These days if I eat less than 1500 I get signs that my body isn't getting enough.. I am losing weight on 1600-1900 a day

anyway- last line- super important.

Could you have survived on that 1200? sure- but that's the crux of the situation- WHY would you want to eat that little when you can accomplish the SAME EXACT GOAL of losing weight and not make yourself miserable. That's really all it boils down to. If you can lose weight AND still eat? How is this not a win win!!!!

Exactly... It's so hard to convince those that eat 1200 to up their calories, but once they do they will be so much more likely to continue their weight loss!

This is posted for people who are not eating properly over a long period of time.

Got it.

This is a public service announcement warning women about the imminent danger of hairy backs?

So, bottom line, starvation can lead to death....?

Is that what we're talking about here?