Lowered metabolism - why is this a problem?

(Doug) #61

Brunneria, I would love to have a home tester for metabolic rate. Fung’s figure of 14% metabolic increase in the fourth day of fasting was an average, and indeed - one wants to know what’s going on with themself on in individual basis. ~$3000 though, for a used testing machine, and there are some consumables that get used up, which adds to the cost. :frowning_face:

(mole person) #62

This is an excellent question. The body needs few things. It must have a certain amount of protein to maintain it’s lean mass, it must have a certain amount of fuel to keep up with a healthy resting energy expenditure and it must have some nutrients.

Let’s tackle the first two. There are a huge amount of differences of opinion on how much protein per kg of lean mass is required for basic maintenance. I’ve heard numbers from .4 to 1.5. Also, even if we were able to settle on the perfect number that too would just be an average requirement. There is data suggesting massive differences in these requirements across individuals.

Second, every tissue and every organ in your body has metabolic needs for fuel and/or maintenance and repair. Fat has the lowest at 2 calories/lb/day and muscle is the next lowest at 6 calories/lb/day. By far the majority of your resting energy requirements are from your organs; the maintenance and functioning of your brain, liver, lungs, kidneys, heart, skin, glands, bone, and intestines. These account for about 70-80% of your resting metabolic energy expenditures.

I’ve done some back of the envelope math to figure the metabolic needs of the organs alone and in the average human it accounts for roughly 1200 calories. This number will be higher for men who have slightly larger organs and smaller for women, but the difference is not that huge.

So let’s figure at the absolute low end 900-1000 calories JUST for organ maintenance and function in a typical woman and this does not include any fuel for maintaining muscle mass. On a pound for pound basis muscle is very cheap metabolically but we have a fair bit of it. Even a small woman like I am at 112 lbs is about 35% muscle. That’s 40 lbs at 6 calories per pound, or 242 calories. I won’t even add the needs of fat, but really you should since we actually do need a certain % of fat on our body. But for my body that would only be an additional 40 calories a day.

So as you can see, when you add it all together the NEEDS of the body come pretty near the 1200 calorie average that’s thrown around so commonly for women.

(Omar) #63

what I understood from Dr Lee Know is the more excess calories you ingest, the more mitochondrial damage takes place.

So the excess calories will spell out of the electron chain becoming free radicals and oxidize in a very close proximity to the mitochondria causing damage.

unless we are talking about different things what i quoted you saying may not be correct.

#64

And what metrics would indicate those needs are not being met? Blood tests on kidney function? Liver? Thyroid? Platelets? Metabolic panel?

(mole person) #65

It’s actually easier than that. Your body attacks its fat first. If you have a reasonable amount of fat still on your body you just needn’t worry.

The thing that got me so interested in this question when I saw it today is that my niece is currently in hospital on bed rest, and has been for the last 3 weeks because she dieted herself practically to heart failure. But my sister was absolutely freaking out for weeks before this because her daughter first lost pretty much every ounce of body fat she had.

(Anne Brodie) #66

I follow what you are saying. How are you calculating the metabolic needs of the organs?

(Anne Brodie) #67

I am so sorry to hear about your niece! Heart issues are common with anorexia and other eating patterns that don’t provide enough calories. So heart issues would be possible indicators.

(Anne Brodie) #68

Exactly! You asked my question much more clearly than I.

(mole person) #69

I took the data from the table in this paper:

https://bodyrecomposition.com/research-review/dissecting-the-energy-needs-of-the-body-research-review.html/](https://www.google.com/url?q=https://bodyrecomposition.com/research-review/dissecting-the-energy-needs-of-the-body-research-review.html/&sa=D&source=hangouts&ust=1535052819904000&usg=AFQjCNHq6yFyFaLxFzEN0IgmYKHB5GZIwQ)

but the data originated in the following:

Elia M. Organ and tissue contribution to metabolic rate. In: Kinney JM, Tucker HN, editors. Energy Metabolism: Tissue Determinants and Cellular Corollaries. Raven Press; New York: 1992. pp. 61–80.

(mole person) #70

The tell was that her heart rate was too slow. It was at 35 bpm when they took her to hospital but they won’t let her out of bed until her resting rate is above 50 bbm every minute for an entire day. I’m sure that number would be different for athletes. But there was no obvious heart failure, in fact she was on the treadmill at the gym when they called to tell my sister to bring her to the hospital pronto.

(Anne Brodie) #71

Low heart rate is a potential warning sign then.

How scary for your sister.

(mole person) #72

Everything Fung and the dudes says is correct on this point. There is no difference between fat on your body or fuel from your plate. If you have decent stores of fat your resting metabolic energy needs can be met from there. Only your protein requirements cannot.

i did assume though that @annecbrodie was probably slim since she said she always eats much less than what are considered normal requirements. I realize now that that might have been a mistake.

(mole person) #73

Yes, but a serious one. Her heart muscle was compromised. Now she has to lie in bed and eat for weeks while her body repairs the damage and it’s gone much slower than the doctors expected. Further, I’d expect her other organs are compromised also.

(Anne Brodie) #74

Thanks, @Ilana_Rose. I was overweight, but that has changed. I totally agree on the dudes and Fung and using fat from eating or fat from the doughnut, and it worked great for me. I have not lost muscle and in fact have gained it. My fat % is quite low but I have excess skin. My blood pressure and other blood work is all great except for high LDL and because of Dave Feldman I think I know what is going on there and am going to a new doctor this Friday to find out more.

What I think has happened is that lesser food quantities helped me lose because my body fat filled in the rest but now that I don’t have as much fat I might need more food. I’m working to find out objective ways to determine if this is true and how to tell how much is too much or too little. If I am not eating enough to fuel my basic organ needs, what is other proof to show that (or not)? If I keep losing weight below my “normal” range for example, that would be an indicator. Or if my heart rate was 40 that would be an indicator. People have mentioned being cold or having lower body temperature but those two things have been true for me throughout life regardless of weight. But they would be clues for people who have not had those in the past.

(Anne Brodie) #75

Yes, very. I did not mean to imply otherwise. I am figuring that other signs/problems happened before this point. As you say, other organs being compromised.

(mole person) #76

I’m going out for a bit, but I will make a complete answer to your last posts when I return. What would you say your body fat % is right now?

(Anne Brodie) #77

According to the machine at the gym, 16%. According to the scale of a friend, 24%

#78

Yes. But THAT was the point of my question – what metrics would indicate one SHOULD worry? For example, primarily using muscle tissue for necessary proteins and/or energy once fat stores are gone? (Is that called catabolysis?)

(Omar) #79

I think the metrics is the waste size (belly fat)

just a thought

(mole person) #80

There are going to be some few among us here that have eating disorders and you can never really be certain who that might be, but I generally assume I’m not talking to one such without good reason since most of us are not. My general feeling is you shouldn’t worry too much about getting too thin. Most of us just won’t like how we look long before we get to an seriously unhealthily low body fat level and will just eat more to avoid it. I don’t like it when people here tell someone how many calories they “should” be getting for their size, or that they weigh too little for their height based on some published ranges. We are all too different. Basically, if you think you still have enough body fat on your body then you are probably, almost certainly, just fine.