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Comment by mathgeek | Hacker News Reader

Not sure I follow the logic here, but happy to be proven wrong if I'm misunderstanding. It's not intuitive to me that a 300 lb. person at 20% body fat is generally at the same risk as a 200 lb. person at 30% body fat.

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Fat is inherently unhealthy for you beyond some low baseline level.

Additional muscle is positive for health, but only up to some reasonable threshold. There is no health benefit to having very high levels of muscle, and in fact it may be negative for your health at extreme levels. E.g. many bodybuilders have trouble breathing, sleep apnea etc.

Both people in the example have 60lbs of fat. 1lb of muscle doesn't cancel out the negative health effect of 1lb of fat

Do short people have much lower risk of heart disease?

Some are more common in short people and some are more common in tall people. Hypertension is one of the ones more common in short people and is significantly more common than the rest combined, so your overall chance of having some form of heart disease goes down as you get taller. However, the forms of cardiovascular disease more common in tall people (e.g. atrial fibrillation) are more likely to actually kill you.

The mean height for men at 20-29 is 69.2" and 80+ is 67.1" (measured in 2015-2018, the last data I've found) [1], which could be interpreted as shorter people having lower risk of all mortality. One could say that people are just getting taller over time and 80+ y.o. were shorter at their 20-29, but we also have the median height for 20-29 fro 1970s, when 2018's 80+ were 20-29 - it's actually 69.7" [2], men in the US are getting shorter over time, so unless people naturally shrink 2" with age the data points to shorter people having lower risk of death.

1. https://www.cdc.gov/nchs/data/series/sr_03/sr03-046-508.pdf

2. https://www.cdc.gov/nchs/data/ad/ad347.pdf

Short people have fewer incidences of cancer, so I don’t think you can say that lower overall risk of death implies lower risk of heart disease.

As for 2, men in the US are getting shorter because of immigration which adds many confounders.

I am not saying that. I am saying that the theory about absolute amount of fat being bad for health, as stated by the comment you responded, seems to be supported by data.

That’s not the question I ask though. I asked about the specific claim that absolute fat was bad for your heart.

But also short people living longer has so many more possible explanations than less overall fat.

> I asked about the specific claim that absolute fat was bad for your heart.

There is no word "heart" or any to this effect in the message you replied to so I did not understand that was what you were doing. I took your question as an attempt to attack the theory on the basis of prevalence of some heart conditions in shorter people.

No that’s not what I was getting at. The post was edited and originally mentioned absolute amount of fat being bad for your heart.

People do tend to shrink in height quite a bit at advanced age.

https://medlineplus.gov/ency/article/003998.htm

"People typically lose almost one-half inch (about 1 centimeter) every 10 years after age 40. Height loss is even more rapid after age 70. You may lose a total of 1 to 3 inches (2.5 to 7.5 centimeters) in height as you age."

So people DO in fact tend to lose about 2 inches at age 80 versus their younger selves.

The actual studies [1],[2] that tried to measure this came to very different rates of height loss though: 3.6 cm and 6 cm from 40 to 80 in men. This does not look like a serious fact.

1. https://pubmed.ncbi.nlm.nih.gov/10547143/

2. https://www.mdpi.com/2072-6643/15/21/4694 (referencing the FHS there, the numbers are hard to find on the study's website).

Even the low end of 3.6cm is 1.4 inches. Feels like you're being rather...goal post movey.

There is no "low end" , such a huge difference shows that both studies are not reliable.

The difference was 3.6cm in the study that measured 10 more years 30-80. And 5cm in the study that measured 10 fewer years 40-80.

The studies were conducted over different time periods when average nutrition changed, and demographics changed. And the study demographics just vary by location.

Height loss with age is incredibly well documented. Here’s a few more studies.

This is just basic medical textbook information. No one in the world is arguing that this phenomenon doesn’t exist.

https://pubmed.ncbi.nlm.nih.gov/32611342/

https://pubmed.ncbi.nlm.nih.gov/24962157/

https://pubmed.ncbi.nlm.nih.gov/10602346/

https://www.sciencedirect.com/science/article/pii/S266703212...

Now, who is moving goalposts?

No one:

Again, from your OP: "so unless people naturally shrink 2" with age"

Are you denying basic science here, or what? Like, what is your deal?

Read what I wrote, read what you wrote. If you still don't get it - ask a chatbot, though you obviously understand and are just trolling.

I’m also confused.

Looking for some references on these claims, thanks! What you're saying registers as "makes some sense, but where's the evidence?" to me. I'm not seeing the connection where total lbs of fat is inherently worse than higher percentage.

You won’t find any reference for those claims. Did you know that the majority of people who have heart attacks have normal lipid levels?

It’s not the fat that kills. It’s oxidated lipids that kill.

I haven’t heard that as a cause of heart attacks. Is “oxidated lipids” the phrase to look for in research?

Yes. Rather, Oxidated LDL for heart disease specifically.

https://www.sciencedirect.com/science/article/abs/pii/S24518...

The claim that fat is inherently unhealthy is probably too broad.

From what I have heard from doctors, there is a clear sequence:

intra-organ fat (really bad) > visceral fat (quite bad) > subcutaneous fat (relatively harmless).

The nasty detail is that some people gain relatively more visceral fat than others. These three fats are correlated, but the correlation isn't the same in every human. Some have better metabolism and don't store as much fat inside as others do.

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