Calories per Pound

[salilphatak]

Jordan,

Almost all calorie calculator websites seem to use this ‘3500 calories = 1lb’ thumb rule when calculating calorie intake. How accurate is that assumption and how much can it vary from person to person?

For me personally (5ft 10, 172lbs) the TDEE number seems to be ~2900. Based on this, I should be losing 1lb a week by eating ~2400 calories. However, I am currently losing 1lb per week while eating 2600 calories. So for me is 2800 calories = 1lb instead of 3500? Or is my TDEE actually around 3100?

Thanks.

[Jordan_Feigenbaum]

All Calorie calculators are rough estimates for energy intake. They should be used to ballpark an individual’s Calorie target and then adjusted based on results.

I would recommend this one:

Body Weight Planner - NIDDK

As far as the 3500 Calories= 1 pound “rule of thumb”, which refers to the idea that an individual needs to achieve an energy deficit of 3500 Calories to lose 1lb, you are correct in assuming it is inaccurate and varies from person to person.

For example, individuals with greater levels of body fat require a higher energy deficit per pound loss and when losing more lean body mass, smaller deficits are needed.

I don’t know what your TDEE is and don’t think that sussing out the difference between a few hundred Calories is going to make a difference, not that you could do this at home anyway. If you’re losing weight to the tune of ~ 2-3% BW per month, keep doing what you’re doing.

[salilphatak]

Thanks Jordan. Just wanted to know whether I will stop being in a deficit if I switched to whole milk for my latte instead of almond.

[The_Average_Lifter]

For clarification, is it somewhat accurate to say that 1 lb fat = 3500 kcal and 1 lb muscle = 700~ kcal?

[Jordan_Feigenbaum]

@salilphatak

Thanks Jordan. Just wanted to know whether I will stop being in a deficit if I switched to whole milk for my latte instead of almond.

It’s not really possible to say.

[Jordan_Feigenbaum]

@The_Average_Lifter

For clarification, is it somewhat accurate to say that 1 lb fat = 3500 kcal and 1 lb muscle = 700~ kcal?

Not really, no.

The 3500 Calorie “rule” posits that an energy deficit of 3500 Calories is required to lose 1 pound of body fat. This rule assumes an exclusive loss of adipose tissue and that 1 gram of fat contains 9 Calories of energy.

Adipose tissue is ~87% fat and also contains protein and water. 87% of 1 pound is 394 grams and at 9 Calories per gram yields 3546 Calories. Thus, a 3500 Calorie energy deficit= 1lb of weight loss, right?
Eh, not quite for a few non-measurement-related reasons:

1. people lose lean body mass in concert with fat mass
2. people can actively compensate to energy deficits in various ways to create smaller or larger than predicted weight loss
3. the resultant energy deficit needed to lose weight changes over time, e.g. individuals with greater levels of body fat require a higher energy deficit per pound lost Measurement-wise, there are additional issues:
4. Doubly-labeled water, the gold standard for measuring total daily energy expenditure outside the lab, has a ~ 5% measurement error and makes determining small changes in energy balance difficult
5. Energy intake in individuals outside of metabolic ward trials is also very difficult to measure
6. Weight change in humans, particularly achieving a new steady state, takes much longer than expected, e.g. close to a year. Using short-term changes (1-2 weeks) makes determining energy balance and its subsequent effects difficult.

In any case, the present evidence seems to suggest that every permanent 10 Calorie reduction per day will produce 1lb of weight loss when the bodyweight reaches a new steady state, which will take years.

While it’s very difficult to manage Calories with that level of precision, adjusting an individual’s food and eating environments along with other aids to improve satiety (e.g., exercise, medication, and surgery if indicated) produce spontaneous reductions in energy intake to long-term achieve weight loss.

With respect to muscle mass, the energy stored is ~564 Calories per pound and is made up of 65% protein, 44% fat, and 2% glycogen. We don’t know how much of an energy deficit is needed to lose “1 pound of muscle”, but most weight loss studies show ~ 75% of weight loss from body fat. This can be manipulated with exercise (particularly RT), diet (protein, carbohydrate, and energy deficit), sleep (less sleep= more LBM lost), and other factors.

Similarly, we don’t really know how much of a surplus is needed to gain 1 pound of muscle. It’s somewhat complicated to calculate, as it has to account for the energy costs of synthesizing muscle and its supportive infrastructure, combating muscle breakdown, storing energy (glycogen and fat), etc. on top of the body’s metabolic costs. Current estimates put the cost of creating 1lb of skeletal muscle is ~ 3700 Calories, though this is also influenced by time.

[salilphatak]

Thanks Jordan. Using the estimator as a starting point then adjusting daily calorie intake based on changes in body weight seems to be the way to go. I had turned off the budget calculator on the app I’m using (Lose It) and started to set my own budget. Glad to know I did the right thing. Previously, I used to base my budget off of my Garmin tracker and that was laughably inaccurate.

[The_Average_Lifter]

@Jordan_Feigenbaum

Not really, no.

The 3500 Calorie “rule” posits that an energy deficit of 3500 Calories is required to lose 1 pound of body fat. This rule assumes an exclusive loss of adipose tissue and that 1 gram of fat contains 9 Calories of energy.

Adipose tissue is ~87% fat and also contains protein and water. 87% of 1 pound is 394 grams and at 9 Calories per gram yields 3546 Calories. Thus, a 3500 Calorie energy deficit= 1lb of weight loss, right?
Eh, not quite for a few non-measurement-related reasons:

1. people lose lean body mass in concert with fat mass
2. people can actively compensate to energy deficits in various ways to create smaller or larger than predicted weight loss
3. the resultant energy deficit needed to lose weight changes over time, e.g. individuals with greater levels of body fat require a higher energy deficit per pound lost Measurement-wise, there are additional issues:
4. Doubly-labeled water, the gold standard for measuring total daily energy expenditure outside the lab, has a ~ 5% measurement error and makes determining small changes in energy balance difficult
5. Energy intake in individuals outside of metabolic ward trials is also very difficult to measure
6. Weight change in humans, particularly achieving a new steady state, takes much longer than expected, e.g. close to a year. Using short-term changes (1-2 weeks) makes determining energy balance and its subsequent effects difficult.

In any case, the present evidence seems to suggest that every permanent 10 Calorie reduction per day will produce 1lb of weight loss when the bodyweight reaches a new steady state, which will take years.

While it’s very difficult to manage Calories with that level of precision, adjusting an individual’s food and eating environments along with other aids to improve satiety (e.g., exercise, medication, and surgery if indicated) produce spontaneous reductions in energy intake to long-term achieve weight loss.

With respect to muscle mass, the energy stored is ~564 Calories per pound and is made up of 65% protein, 44% fat, and 2% glycogen. We don’t know how much of an energy deficit is needed to lose “1 pound of muscle”, but most weight loss studies show ~ 75% of weight loss from body fat. This can be manipulated with exercise (particularly RT), diet (protein, carbohydrate, and energy deficit), sleep (less sleep= more LBM lost), and other factors.

Similarly, we don’t really know how much of a surplus is needed to gain 1 pound of muscle. It’s somewhat complicated to calculate, as it has to account for the energy costs of synthesizing muscle and its supportive infrastructure, combating muscle breakdown, storing energy (glycogen and fat), etc. on top of the body’s metabolic costs. Current estimates put the cost of creating 1lb of skeletal muscle is ~ 3700 Calories, though this is also influenced by time.

Thanks for the detailed post. A few questions:

1. Does that mean that if my current maintenance was at 2000 kcal and I managed to theoretically consume 1990 kcal everyday for a year, I would roughly weigh 1 lb less after a year and it would be a new baseline weight afterwards as long as I don’t drastically vary my energy intake for long periods of time?

2. Does one have an advantage over the other - increasing activity levels vs downsizing food intake to create a deficit? Given that they are already meeting current min guidelines for exercise and will be compliant to both strategies?

3. From the little knowledge I have, I think the best way to have a high TDEE (so we have bigger budget for tasty foods) over the long-term, that is viable to improve as much lean mass (fat mass counts, but I think that would be unhealthy), meet the min aerobic activity guidelines and eat a diet rich in fibre and protein. Would you add anything to this which would be significant and practical?

4. And 44% fat in muscle tissue? Dang! My pecs are more marbled than a rib eye. On a serious note, I hope you meant to say water.

If any of the questions need a separate thread on their own, please let me know. I’ll do it.

[Jordan_Feigenbaum]

@The_Average_Lifter

Thanks for the detailed post. A few questions:

1. Does that mean that if my current maintenance was at 2000 kcal and I managed to theoretically consume 1990 kcal everyday for a year, I would roughly weigh 1 lb less after a year and it would be a new baseline weight afterwards as long as I don’t drastically vary my energy intake for long periods of time?

2. Does one have an advantage over the other - increasing activity levels vs downsizing food intake to create a deficit? Given that they are already meeting current min guidelines for exercise and will be compliant to both strategies?

3. From the little knowledge I have, I think the best way to have a high TDEE (so we have bigger budget for tasty foods) over the long-term, that is viable to improve as much lean mass (fat mass counts, but I think that would be unhealthy), meet the min aerobic activity guidelines and eat a diet rich in fibre and protein. Would you add anything to this which would be significant and practical?

4. And 44% fat in muscle tissue? Dang! My pecs are more marbled than a rib eye. On a serious note, I hope you meant to say water.

If any of the questions need a separate thread on their own, please let me know. I’ll do it.

1. Pretty much, though this change seems to take > 12 months to complete in most folks.

2. Increasing activity doesn’t really work, save for the improved satiety compared to sedentary. Reducing food intake is the key here.

3. LBM is the main driver of resting energy expenditure, but also the biggest biological driver of appetite. I’m not sure that we should be aiming to increase LBM to eat more, because you’re going to want to eat more…

4. 44% from an energy storage perspective, not by weight

[The_Average_Lifter]

@Jordan_Feigenbaum

1. Pretty much, though this change seems to take > 12 months to complete in most folks.

2. Increasing activity doesn’t really work, save for the improved satiety compared to sedentary. Reducing food intake is the key here.

3. LBM is the main driver of resting energy expenditure, but also the biggest biological driver of appetite. I’m not sure that we should be aiming to increase LBM to eat more, because you’re going to want to eat more…

4. 44% from an energy storage perspective, not by weight

Thanks for the reply, Dr.

For clarification on the last question, you meant that out of the ~564 kcal stored in 1 lb of muscle, 65% comes from protein, 44% from fat and 2% from glycogen? Is there an error here, because the summation is more than 100% (or my understanding is incorrect :))?

And from these numbers, I think we can assume that the composition in 1 lb of muscle is roughly 90g protein, 25g fat and 3g glycogen, with the rest being mostly water?

[Jordan_Feigenbaum]

@The_Average_Lifter

For clarification on the last question, you meant that out of the ~564 kcal stored in 1 lb of muscle, 65% comes from protein, 44% from fat and 2% from glycogen? Is there an error here, because the summation is more than 100% (or my understanding is incorrect :))?

There are error bars on these numbers, but yes, these are the relative proportions.