Science and math for weight loss
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55in13
Posts: 1,091 Member
I will attempt to keep this from becoming a debate about specific theories. This is just some general info that you can use to test the validity of theories and draw your own conclusions.
A pound of fat is roughly 3500 calories. That's about how much surplus in your diet it takes to create one and how much deficit it takes to lose one.
A pound of fat can only metabolize at a rate of 31.4 calories per day. So if you weigh 200 pounds and have 30% BF, you have 60 pounds of fat capable of supplying up to 1884 calories per day when you are in deficit. That's why obese people can tolerate huge deficits early on.
A pound of muscle only supplies 600 calories.
You can take those 3 things and perform calculations to prove or disprove the validity of a lot of assertions about whether someone is losing fat versus muscle, though you do need a little fudge factor for water weight lost at the beginning (generally around 5 pounds).
In studies, less than 1% of people have a BMR below 1000. There are some special snowflakes but it is highly unlikely that you have a TDEE below 1200.
It is extremely difficult to burn 1000 calories in an hour. Most people never do this. It is an achievable high water mark but unless you are an elite athlete, you probably are not doing this every time you go to the gym.
If you consume less calories than you expend, you will lose wight. If that doesn't seem to be the case then one of your numbers is incorrect.
A pound of fat is roughly 3500 calories. That's about how much surplus in your diet it takes to create one and how much deficit it takes to lose one.
A pound of fat can only metabolize at a rate of 31.4 calories per day. So if you weigh 200 pounds and have 30% BF, you have 60 pounds of fat capable of supplying up to 1884 calories per day when you are in deficit. That's why obese people can tolerate huge deficits early on.
A pound of muscle only supplies 600 calories.
You can take those 3 things and perform calculations to prove or disprove the validity of a lot of assertions about whether someone is losing fat versus muscle, though you do need a little fudge factor for water weight lost at the beginning (generally around 5 pounds).
In studies, less than 1% of people have a BMR below 1000. There are some special snowflakes but it is highly unlikely that you have a TDEE below 1200.
It is extremely difficult to burn 1000 calories in an hour. Most people never do this. It is an achievable high water mark but unless you are an elite athlete, you probably are not doing this every time you go to the gym.
If you consume less calories than you expend, you will lose wight. If that doesn't seem to be the case then one of your numbers is incorrect.
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I will attempt to keep this from becoming a debate about specific theories. This is just some general info that you can use to test the validity of theories and draw your own conclusions.
A pound of fat is roughly 3500 calories. That's about how much surplus in your diet it takes to create one and how much deficit it takes to lose one.
A pound of fat can only metabolize at a rate of 31.4 calories per day. So if you weigh 200 pounds and have 30% BF, you have 60 pounds of fat capable of supplying up to 1884 calories per day when you are in deficit. That's why obese people can tolerate huge deficits early on.
A pound of muscle only supplies 600 calories.
You can take those 3 things and perform calculations to prove or disprove the validity of a lot of assertions about whether someone is losing fat versus muscle, though you do need a little fudge factor for water weight lost at the beginning (generally around 5 pounds).
In studies, less than 1% of people have a BMR below 1000. There are some special snowflakes but it is highly unlikely that you have a TDEE below 1200.
It is extremely difficult to burn 1000 calories in an hour. Most people never do this. It is an achievable high water mark but unless you are an elite athlete, you probably are not doing this every time you go to the gym.
If you consume less calories than you expend, you will lose wight. If that doesn't seem to be the case then one of your numbers is incorrect.
I am firmly of the belief that often, when people say they are eating X amount of calories per day and are not losing weight, they are either overestimating calories burned or underestimating calories in food and drink.
Regarding burning 1000 calories per hour, fully agree! I have burned over 1000 calories, but it has taken significantly longer than one hour, usually 62 minutes or something like that.
j/k :laugh: - it has usually taken near on 90 minutes with much of that being running.0 -
As a general rule, for me at least, if I'm burning about 10-11 calories/minute that's doing great. Therefore about 90 minutes of really hard work would be needed to burn 1,000 calories. And that's pushing it. An hour? I have a couple of friends who are serious bikers who ride really hard so they may, but that is the outlier. For most in a gym, 1000 calories in an hour isn't going to happen.0
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I would be very surprised if someone did it on a bike. It would not surprise me if they did 200 in twelve minutes on a climb, but if the ride was on level ground it would have to be pretty high speed (I would guess maybe 40 mph if the bike is a reasonably good one) with no stops. On rolling terrain it would require dangerous speeds on the downhill parts.0
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I would be very surprised if someone did it on a bike. It would not surprise me if they did 200 in twelve minutes on a climb, but if the ride was on level ground it would have to be pretty high speed (I would guess maybe 40 mph if the bike is a reasonably good one) with no stops. On rolling terrain it would require dangerous speeds on the downhill parts.
40mph, blimey I am hardpushed to go 40mph in my car! :laugh:0 -
All true. As a nutritionist I see the struggles and have my own but it all boils down to the science. Everyone is different too. There is no blanket statement that can be said about how to achieve your goals. The best result is the one that is derived from a lifestyle change and not a diet. Re-wire how we approach these goals.0
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I enjoy riding my bike but I don't think I get a very good burn when I ride. When riding casually, the common method is accelerating to about 20 mph then coasting to about 15, accelerating, coasting, etc, etc, etc. Constant pedaling only on uphill sections and coasting for a while down hill. Anyway, it is a guess on my part about going 40 or so but it would vary depending on the bike. It's whatever speed it would take so that the deceleration effects of wind resistance and friction would require you to pedal hard to keep the speed. There is nowhere near me that I could safely do this.0
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Except the part where I said you will lose "wight". Just noticed that. :ohwell:All true. As a nutritionist I see the struggles and have my own but it all boils down to the science. Everyone is different too. There is no blanket statement that can be said about how to achieve your goals. The best result is the one that is derived from a lifestyle change and not a diet. Re-wire how we approach these goals.
Yes, everyone is different, but no one is immune to the basic physics.0 -
that's about what I burn too, unless my hr gets up over 148-150 on elliptical.. but that's in spurts and I can't maintain that for long. a good 34 or 40 minutes arond 130-140ish is what I usually do, maybe I should PUSH IT to the hour!!! ( I did try 35 min on elliptical the other then and tried the stair climber thing.. but that was just stupid....i don't like the rowing machine either) elliptical is my choice.As a general rule, for me at least, if I'm burning about 10-11 calories/minute that's doing great. Therefore about 90 minutes of really hard work would be needed to burn 1,000 calories. And that's pushing it. An hour? I have a couple of friends who are serious bikers who ride really hard so they may, but that is the outlier. For most in a gym, 1000 calories in an hour isn't going to happen.0 -
OK, I was off quite a bit guessing about how fast you would have to bike.
Here is a chart:
http://www.nutristrategy.com/fitness/cycling.htm
It looks like around 20 mph or a little faster, depending on your weight.0 -
It is extremely difficult to burn 1000 calories in an hour. Most people never do this. It is an achievable high water mark but unless you are an elite athlete, you probably are not doing this every time you go to the gym.
So you're telling me that when my friends post things like "Burned 1,259 calories doing 45 minutes of Aerobics (low impact)" it's not accurate??
Yeah, I actually laughed out loud at a story on my feed yesterday when one of my friends logged over 2,000 calories burned from just over an hour of exercise. Something doesn't feel right, kid. Not right at all. 0 -
With all due respects, that math applies in a perfect world. Unfortunately, that world doesn't exist for many of us and the science is still virtually unknown. Case in point: http://www.ted.com/talks/peter_attia_what_if_we_re_wrong_about_diabetes.html0
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Another factor to stir into your science is the variance between the calculated calories for foods and the realizable energy as far as each human body is concerned. The more I read about the Atwater method and the USDA National Nutrient Database for Standard Reference, the more I wonder how it could be gamed by food manufacturers. And then there are the individual differences in how efficiently our bodies harvest the energy of ingested foods.0
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he gives me the willies...With all due respects, that math applies in a perfect world. Unfortunately, that world doesn't exist for many of us and the science is still virtually unknown. Case in point: http://www.ted.com/talks/peter_attia_what_if_we_re_wrong_about_diabetes.html0 -
My response is contained in the opening sentence of the first post...0
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Interesting. I am in the process of raising my calories to get out of the yo yo dieting cycle. Science supports metabolism BMR, based on size but there don`t seem to be any studies supporting metabolism repair, or are there??0
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I am unaware of any. The studies I have read find a drop in BMR of between 4% and 10% for the vast majority of people when calories are reduced but no point at which reduction of calories doesn't increase deficit. I did not include this in my earlier list because of the disclaimer - "for the vast majority". I think far more people claim to be in the small minority that have more severe changes than truly are, but that's an opinion.Interesting. I am in the process of raising my calories to get out of the yo yo dieting cycle. Science supports metabolism BMR, based on size but there don`t seem to be any studies supporting metabolism repair, or are there??0 -
I was just looking over my runs on Endomondo. I don't have a HRM but I do keep it up to date with my weight. Still, I think its estimates are generous. I went back to a run on July 1 which has all my best times. I was in Chicago on business and ran on the lake front trail in the early AM; nice and flat with nothing that breaks your pace. Anyway, the run was over an hour and over 1000 estimated calories so i used a calculator to figure out what it was at an hour. 998! As I said, I really don't think that was accurate anyway, but it is kinda funny that it came that close. So even a bloated estimate of my best run didn't get me there.Regarding burning 1000 calories per hour, fully agree! I have burned over 1000 calories, but it has taken significantly longer than one hour, usually 62 minutes or something like that.
j/k :laugh: - it has usually taken near on 90 minutes with much of that being running.0 -
Thumbs up!
The TDEE part is what always gets me. People feel like they need to eat "1000 calories or less" or they won't lose weight. One girl I was talking to was eating 5 "120 calorie" shakes a day and that's IT to lose weight. It's very hard to explain to people nutritional principles when they have no background. I mean the same girl (20 years old) did not know how to read nutrition labels either.
I told her "she's not going to drink those shakes the rest of her life" and basically that her cravings would take over and a more realistic calorie intake of around 1400-1600 is a good place to start. Before dieting she tracked her cals on the USDA supertracker and was eating around ~2300 cals a day.0 -
It is extremely difficult to burn 1000 calories in an hour. Most people never do this. It is an achievable high water mark but unless you are an elite athlete, you probably are not doing this every time you go to the gym.
The only thing you're not taking into account with this point is the person's bodyweight. If you weight 300 pounds and are pushing hard doing something like jogging or high intensity aerobics, that number could be pretty easily attainable I think.
I don't know if the relationship is quite linear, but when you think about it, a 300 pound person is going to need around twice the energy to move around than a 150 pound person. Again, it's basic physics.0
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