Is calories in vs calories burn't a myth?

I've always believe calorie in vs calorie out to be true. After working out my base metabolic rate and counting calorie deficits , my weight loss adds up and the sums work. However, my grand mother for example only eats around 1000 calories a day and has done for the last 20 years. How come she doesn't starve to death? She is more active than me throughout the day so it's unlikely that her base metabolic rate is much lower than mine.

Also how do you explain people on a CRON diet? Surely they would lose weight until there was nothing left to lose if calorie in vs calorie out was a sound concept.

Don't want to overcomplicate anything as it works for me ;) Am just naturally curious
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Replies

  • logg1e
    logg1e Posts: 1,208 Member
    You think that your grandmother has a comparable calorie requirement t a 19 year old male, albeit a rather inactive one?
  • girlviernes
    girlviernes Posts: 2,402 Member
    Calorie in vs calorie out holds, but metabolism can shift related to various factors.
  • SezxyStef
    SezxyStef Posts: 15,267 Member
    no it's not a myth and how do you know what your grandmother eats, are you with her every second?
  • PDarrall
    PDarrall Posts: 114 Member
    Yes and no.

    The problem is actually the question itself.
  • simplydelish2
    simplydelish2 Posts: 726 Member
    IMO, calories in vs. calories out is a guide - not an absolute. You have to consider age, metabolism, and other body chemistry when you view calorie requirements.

    The contention that you must eat at a deficit to lose weight however remains a fact.
  • JackPudding
    JackPudding Posts: 37 Member
    No, but have lived with her for periods of time and know that she tends to eat pretty much the same things everyday. I don't see why her BMR would be any lower than mine considering I often barely do any form of activity, sitting must of the day, whereas she walks at least 3 miles a day and does the garden.

    Also how do you explain CRON dieters?
  • DeguelloTex
    DeguelloTex Posts: 6,652 Member
    IMO, calories in vs. calories out is a guide - not an absolute. You have to consider age, metabolism, and other body chemistry when you view calorie requirements.
    How are the factors you list not simply part of an accurate assessment of calories out?
  • vismal
    vismal Posts: 2,463 Member
    It's not a myth. The problem is that people really have a poor idea of how much they eat, even if they log. People also have a poor idea of what they burn. TDEE and BMR calculators are just estimations. Even a heart rate monitor is not 100% perfect. We also don't know what percentage of what we burn is glycogen, fat, muscle, etc. So if you have an imperfect calorie count + an imperfect TDEE combined with the fact that we don't know what our body is using for fuel and the fact that weight loss isn't linear due to water retention, glycogen saturation, etc it can seem like CICO doesn't add up. In reality it does, it ALWAYS does.

    In the long run, if you truly eat less then you burn in a day, weight will go down. It will, for the reasons above, RARELY correlate exactly with how much you THINK or have calculated that it should go down.
  • cwolfman13
    cwolfman13 Posts: 41,865 Member
    It is not a myth...by and large, CICO is the most important factor to controlling weight. What people get all wrapped up in though are absolutes...there is nothing absolute about calorie counting and intake, etc. It's all based on estimation...nobody has a TDEE of exactly XXXX calories, etc. This and other calculators and calorie estimates are just good and reasonable starting points, they aren't set in stone.

    To that end, you also have to consider an individuals age, their lean mass, hormones, nutritional deficiencies, natural slowing of the metabolism when you undereat, etc.

    It is far more complicated that CICO...but CICO is by and large the most important factor. Also, there's no way you can compare yourself as a 19 year old male to your grandmother...so just stop that
  • dont_tap_my_aces
    dont_tap_my_aces Posts: 125 Member
    1) guarantee unless grandma is weighing out everything she eats, shes estimating at best she eats 1000kcals. And we all know where estimation leads us.... 95% of us are on this site thanks to years of 'estimation'

    2) even if that were the case, what's her height/weight compared to you? these factors are pretty important, as a young male age 19 most likely is larger and therefore has more of a caloric/fuel need on a weekly basis than an elderly woman.

    but to answer your question, as the others have stated, No, it's not a myth. it's actually kinda one of the fundamental laws of physics. don't believe the HAES/Fat-logic crowd, calorie in vs calorie out works. you just actually have to measure and be as accurate as possible if you want results. estimation will lead to failure in most people.
  • Liftng4Lis
    Liftng4Lis Posts: 15,151 Member
    You're a 19 year old male, you can't compare yourself to an older woman and you have no idea what she really eats.
  • JackPudding
    JackPudding Posts: 37 Member
    If someone eats half the amount an average person eats and does not lose weight it stands to reason that their metabolism is twice as effective at processing calories. If that person then doubled their calorie in take to around 2000 calories would they then put on weight? This would blow the whole in vs out thing out of the water...

    Btw, it works for me so i'm just playing devils advocate ;)
  • traceywoody
    traceywoody Posts: 233 Member
    Different people have differing caloric needs. Its really that simple.
  • eric_sg61
    eric_sg61 Posts: 2,925 Member
    No, but have lived with her for periods of time and know that she tends to eat pretty much the same things everyday. I don't see why her BMR would be any lower than mine considering I often barely do any form of activity, sitting must of the day, whereas she walks at least 3 miles a day and does the garden.

    Also how do you explain CRON dieters?
    There are many factors and variables between individuals in the calories out part of the equation.
  • vismal
    vismal Posts: 2,463 Member
    No, but have lived with her for periods of time and know that she tends to eat pretty much the same things everyday. I don't see why her BMR would be any lower than mine considering I often barely do any form of activity, sitting must of the day, whereas she walks at least 3 miles a day and does the garden.

    Also how do you explain CRON dieters?
    Why do people not die on the CRON diet, they aren't 100% compliant 100% of the time, that's how.
  • oksanatkachuk
    oksanatkachuk Posts: 149 Member
    But yet we saw ppl die from starvation around the world. Some faster, some slower. Malnutrition will weaken the organs and eventually will kill.
    Thermodynamics is a proven fact.

    The Q is how long it will take to die from lack of calories + very difficult to be sure if one is in true deficit constantly.
  • TeaBea
    TeaBea Posts: 14,517 Member
    It's not a myth.

    Some people have slower metabolisms: thyroid, elderly, very petite, body fat to muscle ratio

    Some people just think they are eating only 1,000 calories

    Some people just think they are active, or lightly active (whatever)
  • tomcornhole
    tomcornhole Posts: 1,084 Member
    1900 = BMR of 19 year old male, 160 lbs, 5' 10"
    1000 = BMR of 70 year old female, 110 lbs, 5' 4"

    Does that answer your question?
  • defauIt
    defauIt Posts: 118 Member
    Your question is like asking if gravity exists, how do planes fly?!

    Calories in vs. calories out is very basic science and a proven fact. The reason why people don't think it works is because we have to estimate both sides of the equation and that estimation always has some error attached. If someone is over estimating the calories they burn and underestimating the calories they eat, they can very easily turn a minor deficit into a surplus. Instead of thinking to themselves "I must have made an error somewhere", they instead assume they're perfect and special and the laws of physics don't spply to them.
  • JackPudding
    JackPudding Posts: 37 Member
    @vismal This makes sense to me actually.

    Is it possible that a metabolism adjusts to a lower calorie intake? Or is that just complete BS.

    It is surprising that different people's BMR's or required calorie intake can be so far apart. Is this the reason it is possible for some people to be able to eat massive calorie surplus without putting on weight because really it technically isn't a surplus but a variety of different factors such as a fast metabolism/ high energy requirements. If this was true it would stand to reason that their is such a thing as a fat gene and skinny one...
  • JackPudding
    JackPudding Posts: 37 Member
    Your question is like asking if gravity exists, how do planes fly?!

    Calories in vs. calories out is very basic science and a proven fact. The reason why people don't think it works is because we have to estimate both sides of the equation and that estimation always has some error attached. If someone is over estimating the calories they burn and underestimating the calories they eat, they can very easily turn a minor deficit into a surplus. Instead of thinking to themselves "I must have made an error somewhere", they instead assume they're perfect and special and the laws of physics don't spply to them.

    Its not just a 'law of physics' because humans aren't some form of bloody battery. We don't process 100% of energy that enters our body. A persons metabolism determines this.
  • vismal
    vismal Posts: 2,463 Member
    @vismal This makes sense to me actually.

    Is it possible that a metabolism adjusts to a lower calorie intake? Or is that just complete BS.

    It is surprising that different people's BMR's or required calorie intake can be so far apart. Is this the reason it is possible for some people to be able to eat massive calorie surplus without putting on weight because really it technically isn't a surplus but a variety of different factors such as a fast metabolism/ high energy requirements. If this was true it would stand to reason that their is such a thing as a fat gene and skinny one...
    People's metabolisms are vastly different for many many reasons. Genetics play a huge role. Also people who are very active simply burn more calories a day via their activity. When you diet for long periods of time you can have some slowdown to your metabolism. It's never going to be enough to make weight loss stop or cause weight gain. Anytime you are not losing weight in the long run when you think you are in a deficit you need to examine a few things. More often then not you are simply eating more then you think. I would say 80% of the time this is the case. Other times people, sometimes unconsciously, become less active during prolonged deficits. Both these examples still fall within CICO. To sum it up, if you aren't losing weight (again in the long run), you're eating too much, you're burning too little, or both.
  • JackPudding
    JackPudding Posts: 37 Member
    @vismal This makes sense to me actually.

    Is it possible that a metabolism adjusts to a lower calorie intake? Or is that just complete BS.

    It is surprising that different people's BMR's or required calorie intake can be so far apart. Is this the reason it is possible for some people to be able to eat massive calorie surplus without putting on weight because really it technically isn't a surplus but a variety of different factors such as a fast metabolism/ high energy requirements. If this was true it would stand to reason that their is such a thing as a fat gene and skinny one...
    People's metabolisms are vastly different for many many reasons. Genetics play a huge role. Also people who are very active simply burn more calories a day via their activity. When you diet for long periods of time you can have some slowdown to your metabolism. It's never going to be enough to make weight loss stop or cause weight gain. Anytime you are not losing weight in the long run when you think you are in a deficit you need to examine a few things. More often then not you are simply eating more then you think. I would say 80% of the time this is the case. Other times people, sometimes unconsciously, become less active during prolonged deficits. Both these examples still fall within CICO. To sum it up, if you aren't losing weight (again in the long run), you're eating too much, you're burning too little, or both.

    Okay you've restored my faith in calorie in vs out. But it's not as simple as people make it out to be. It not just X + Y = Z. I naturally assumed that the in vs out was set at 2000 calories for a women and 2500 for a man or there abouts. However, this actualy doesn't have be the case. I think however as a basis to successful weight loss as long as you know roughly your daily calorie requirements to just maintain C in vs C out is a good starting point to loose weight
  • defauIt
    defauIt Posts: 118 Member
    Your question is like asking if gravity exists, how do planes fly?!

    Calories in vs. calories out is very basic science and a proven fact. The reason why people don't think it works is because we have to estimate both sides of the equation and that estimation always has some error attached. If someone is over estimating the calories they burn and underestimating the calories they eat, they can very easily turn a minor deficit into a surplus. Instead of thinking to themselves "I must have made an error somewhere", they instead assume they're perfect and special and the laws of physics don't spply to them.

    Its not just a 'law of physics' because humans aren't some form of bloody battery. We don't process 100% of energy that enters our body. A persons metabolism determines this.

    You're attacking a strawman, I never said we process 100% of everything we eat. The amount of calories you can absorb from your food is part of the calories in side of the equation if you do it properly.
  • JackPudding
    JackPudding Posts: 37 Member
    Your question is like asking if gravity exists, how do planes fly?!

    Calories in vs. calories out is very basic science and a proven fact. The reason why people don't think it works is because we have to estimate both sides of the equation and that estimation always has some error attached. If someone is over estimating the calories they burn and underestimating the calories they eat, they can very easily turn a minor deficit into a surplus. Instead of thinking to themselves "I must have made an error somewhere", they instead assume they're perfect and special and the laws of physics don't spply to them.

    Its not just a 'law of physics' because humans aren't some form of bloody battery. We don't process 100% of energy that enters our body. A persons metabolism determines this.

    You're attacking a strawman, I never said we process 100% of everything we eat. The amount of calories you can absorb from your food is part of the calories in side of the equation if you do it properly.

    You're right. But it's not as simple as its made out to be. There a huge number of variables on both sides of the formula. Thanks for the reply ;)
  • LiminalAscendance
    LiminalAscendance Posts: 489 Member
    However, my grand mother for example only eats around 1000 calories a day and has done for the last 20 years.

    So you've weighed and tracked your grandmother's intake every day over the last 20 years?

    You two must be very close.
  • defauIt
    defauIt Posts: 118 Member
    You're attacking a strawman, I never said we process 100% of everything we eat. The amount of calories you can absorb from your food is part of the calories in side of the equation if you do it properly.

    You're right. But it's not as simple as its made out to be. There a huge number of variables on both sides of the formula. Thanks for the reply ;)

    Let me just clarify - the equation is incredibly simple, but there are a huge number of factors involved, making it very difficult to ever calculate super accurately. The question was, "is calories in vs calories burnt a myth?" and the answer is 100% that it is NOT a myth.

    That doesn't mean it's simple or easy for everyone to calculate. Everyone has a different calories out, even if they weigh the same and do the same stuff.
  • meganjcallaghan
    meganjcallaghan Posts: 949 Member
    well according to the articles i've read (granted, they are on the internet and potentially subject to inherent interwebby stupidity) your metabolism is reduced by about 1% a year after approximately 30 ish unless you keep up a decent amount of muscle, therefore it is not even remotely surprising that your grandmother could eat so much less than you to maintain
  • bridgie101
    bridgie101 Posts: 817 Member
    No, but have lived with her for periods of time and know that she tends to eat pretty much the same things everyday. I don't see why her BMR would be any lower than mine considering I often barely do any form of activity, sitting must of the day, whereas she walks at least 3 miles a day and does the garden.

    Also how do you explain CRON dieters?


    Not trying to be mean but what does granny drink? And does she ever visit anyone or eat a biscuit or two? Do you watch her down at the shop, and is she eating a cake and a coffee on supermarket day?

    You may know some of the basics of what she eats but you won't have factored in the perks. You certainly don't know how many shots of whiskey she knocks back at 2am.

    Also you do not state her age, or her weight or her height. If she's four foot tall weighing 70lb then 1000 cals is probably a reasonable maintenance quantity.

    The older you get, the fewer calories you need a day. the smaller you are, the fewer calories you need. The more female you are the fewer calories you need. She's all three.

    You can't change the first law of thermodynamics just because you don't think Granny's eating enough to sustain herself. If she is being sustained, she is eating enough to sustain herself. Don't amend the entire global realm of physics for the last 2000 years just to serve your concerns about granny.
  • JackPudding
    JackPudding Posts: 37 Member
    However, my grand mother for example only eats around 1000 calories a day and has done for the last 20 years.

    So you've weighed and tracked your grandmother's intake every day over the last 20 years?

    You two must be very close.

    She's someone who generally isn't interested in food and views it as only fuel. She honestly eats pretty much the same thing everyday. I've quizzed her on this as well, i'm not making any crass assumptions ...