How do I know when my body is in starvation mode?

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  • grinch031
    grinch031 Posts: 1,679
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    My guess is that if your body wants to conserve energy, that you would feel tired, unmotivated and not want to exercise? Otherwise you are fueling your exercise from nothing.
  • AbsoluteNG
    AbsoluteNG Posts: 1,079 Member
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    http://www.ehow.com/how-does_4623846_anorexia-affect-body.html

    http://www.ajcn.org/content/56/1/230S.full.pdf

    http://www.medhelp.org/posts/Heart-Disease/Heart-Palpitations-caused-by-self-starvation/show/255120

    http://www.bulimia.com/client/client_pages/medical_dangers_anorexia.cfm
  • aliceguy
    aliceguy Posts: 128 Member
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    Just going back to the starvation mode bit for a minute, would it not depend on how overweight you are in the 1st place? If you are fairly lean with just a bid of padding and not far off your ideal BMI, I could accept that easier than say if your BMI put you in the obese category and your body had an abundance of fat to burn and enjoy life with.

    So my question is, if you are obese and went on a very calorie controlled diet (say 500 to 800 calories a day for a male) why would the body go into starvation mode when there is fat to burn and use up? Serious question, not being a smart *kitten*...
  • grinch031
    grinch031 Posts: 1,679
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    Just going back to the starvation mode bit for a minute, would it not depend on how overweight you are in the 1st place? If you are fairly lean with just a bid of padding and not far off your ideal BMI, I could accept that easier than say if your BMI put you in the obese category and your body had an abundance of fat to burn and enjoy life with.

    So my question is, if you are obese and went on a very calorie controlled diet (say 500 to 800 calories a day for a male) why would the body go into starvation mode when there is fat to burn and use up? Serious question, not being a smart *kitten*...

    You make a pretty valid point, which is why most of the testimonies of starvation mode are nonsense. Starvation mode is associated more with weight loss and remaining body fat storage levels than with daily calorie intake, although both matter. But the brain needs glucose to function as well, so you can't run solely on fat. When glucose isn't available to fuel the brain, your muscles will start breaking down to produce glucose.
  • o_delaisse
    o_delaisse Posts: 193 Member
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    When you are emaciated. The term "starvation mode" gets thrown around loosely. There are many great informative articles on this myth.

    Exactly. OP, I'm not blaming you for this, but I get so irritated when I see people casually say "you might be in starvation mode". I've been pretty close to starving, and let me tell you - it was not the scales that informed me, it was the fact that I was in absolute agony. As people have already said, "starvation mode" in MFP terms, means a slowed metabolism. And I wish people would say "slowed metabolism" instead of "starvation".

    Again, OP, I am not blaming you for this.
  • yoovie
    yoovie Posts: 17,121 Member
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    Pretty sure that it takes more than 24 hours to go into starvation mode. My PT (and I know physical therapists are not nutritionists and he could well be wrong) said you are most likely to entire starvation mode when you have a total caloric intake for 5-7 days that is less than 4000 calories, depending on each person's individual metabolism, of course.

    And at that point, it is barely beginning and you still have time to turn it around.
  • SHBoss1673
    SHBoss1673 Posts: 7,161 Member
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    Just going back to the starvation mode bit for a minute, would it not depend on how overweight you are in the 1st place? If you are fairly lean with just a bid of padding and not far off your ideal BMI, I could accept that easier than say if your BMI put you in the obese category and your body had an abundance of fat to burn and enjoy life with.

    So my question is, if you are obese and went on a very calorie controlled diet (say 500 to 800 calories a day for a male) why would the body go into starvation mode when there is fat to burn and use up? Serious question, not being a smart *kitten*...

    It's true, the amount of body fat you have will dictate how large your deficit can be. But that does not mean you cannot be obese and still enter starvation mode. Consider a few other factors involved:

    -Starvation mode is a hormonal response that changes how our body prioritizes energy utilization and storage

    -When someone is in starvation mode, the body will reduce energy output as much as possible and increase lipid storage (fat storage)

    -Starvation mode usually doesn't occur until someone has been under eating for at least 3 days. Why 3 days? Because that's about how long (minimum) it takes for your body to burn up glycogen stores, it can take longer (and usually does) if the amount being pulled form glycogen stores is small, but it almost never is shorter (this has been tested numerous times in research).

    -The very basic calculation for whether someone is going to enter starvation mode is this:

    Starvation mode is when the body cannot sustain energetic homeostasis. That means if the calories you consume PLUS the stored energy release rate in the body is less than the calorie needs of the body. Stored energy release rate is classified as how much energy the body can convert from fat the body can mobilize and use at any one time PLUS energy derived from glycogen PLUS energy derived from the conversion of amino acids into ketones. You add stored energy output to the output of calorie intake, look at the concurrency (how much energy is delivered at any one time) and if they don't equal the body's need for energy then you're looking at starvation mode.

    Starvation mode will change the way the body releases hormones, which will trigger changes in many body functions (fat storage, energy use, organ output...etc.)

    If you think this was complicated, try reading the actual explanation, it's killer, I was a chemistry major in college and it still took me 6 months to figure this stuff out.
  • Lolli1986
    Lolli1986 Posts: 500 Member
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    your body will not go into stravation mode untill it has to. it takes a lot for it too, people in here band it around too easily. mfp says if you eat to little it may do because they have to cover themselfs for insurance reasons. plus with those amount of calories you are not even coming near to a VLD which could potentially cause your body to preserve.

    i base my opionion on academic journals i have read, i also base it on university lectures as well as experience in dealing with weightloss as a PT.

    yeah, this ^

    I think the '1200 cals' thing is based on -nutrition-, not energy.

    Also, there is no need to decrease your cals on non-exercise days:

    "Fat is not laid down when there is surplus calories available and stored passively until it is needed; rather, it is constantly being stored in and released from the adipose tissue." ...wikipedia.

    Fat deposition happens whether you're at a surplus or a deficit, so I set my cals to '3500' deficit per week, but otherwise eat the same amount each day, whether I exercise or not.
  • Lolli1986
    Lolli1986 Posts: 500 Member
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    Starvation mode is when the body cannot sustain energetic homeostasis. That means if the calories you consume PLUS the stored energy release rate in the body is less than the calorie needs of the body. Stored energy release rate is classified as how much energy the body can convert from fat the body can mobilize and use at any one time PLUS energy derived from glycogen PLUS energy derived from the conversion of amino acids into ketones. You add stored energy output to the output of calorie intake, look at the concurrency (how much energy is delivered at any one time) and if they don't equal the body's need for energy then you're looking at starvation mode.

    Starvation mode will change the way the body releases hormones, which will trigger changes in many body functions (fat storage, energy use, organ output...etc.)

    If you think this was complicated, try reading the actual explanation, it's killer, I was a chemistry major in college and it still took me 6 months to figure this stuff out.

    ^also an awesome response.
  • sar123bear
    sar123bear Posts: 81
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    bumping :)
  • kalynn06
    kalynn06 Posts: 368 Member
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    Starvation mode has been pretty well hashed out, but if you're worried, you might consider adding more strength training and upping your calories to a number based on looking at your BMR and TDEE. Putting on more lean muscle will do better things for your metabolism in the long run than eating at such a large deficit. I'd be more worried about losing muscle than anything else when eating that low.
  • secretlobster
    secretlobster Posts: 3,566 Member
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    Simply put - Your weight loss stalls, and you may retain water, making you feel bloated or giving you diarrhea.

    The body does not use stored fat as a primary source of energy - We are not tadpoles. That stored fat is slowly burned up when the body regularly doesn't get enough calories to maintain its current MASS.
  • username_1998
    username_1998 Posts: 2
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    Your body will enter starvation mode if you reduce your calories to lower then 50% of what your body normally needs to function.
    Eg; He/she may need 2000 cals/day, they eat 1000 cals or less and there body is at a greater risk of entering starvation mode if lowered intake is continued for longer then a few days.
    Even if you do enter starvation mode you will not stop losing weight, you just might not lose it as fast.
    Hope this helped :laugh: :happy: :wink:

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