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Comment by mensetmanusman | Hacker News Reader

When my mother moved in and we went on daily walks, she lost a pound a week for a year. Her entirely sedentary lifestyle (and that of most Americans I know) is a major factor for her obesity. Standing is now considered exercise it has gotten so bad.

But people will blame anything instead of taking action, so…

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While a sedentary lifestyle causing obesity may be true on an individual basis (and exercise is really really good for you regardless of your weight), it fails to explain why people who do manual labor tend to be as fat or fatter than people who have office jobs and why sedentary people of the past were not that fat compared to people today. There are a lot of reasons detailed in the series about why personal choice cannot adequately explain how it is we are getting fatter as a society. I think there are many good arguments for a non-chemical cause, like more and more appetizing highly processed foods.

But to say "people will blame anything instead of taking action" makes no sense. We have had decades of action trying to get people to eat healthy and exercise. It hasn't done anything. We have to accept that just telling people to lose weight doesn't work and start pursuing other options.

And there are so many good options! In Spain, for example, "staple foods" such as vegetables, meat, and bread are taxed at a lower rate while highly processed foods are taxed at the normal rate. In most developed countries, universal healthcare helps people prevent and manage the worst diseases associated with obesity such as heart disease and diabetes. And yes, we should investigate alternate explanations outside of the exercise/diet nexus such as chemical contamination! It may not be the reason but it is a testable hypothesis that would be "big if true."

Just because a sedentary lifestyle is bad for your health, doesn't mean smoking is harmless.

Do you know anything about these chemical? If so, please share. If not, well, ....

Smoking is an interesting example, Japan smokes a lot more and has less obesity and seems to have higher general health…

Smoking decreases appetite. A lot of people who quit smoking gain significant weight.

Japan has 18% smokers vs. 12.5% in the US. They have a five year longer life expectancy but they also have universal healthcare, so it's not really a fair comparison. Plus, Japan has good air quality and robust elder care.

On top of that, they may have chemical factors (such as no lithium mines) that differentiate them from other developed countries.

I'm pretty sure daily walks (no heart rate elevation, not HIIT, no muscle being built, etc.) didn't contribute significantly to your mother's weight loss. Moving around is not a significant contributor to weight loss[1]. Diet is the most significant contributing factor to gaining or losing weight. Moving in with someone new, new environment, new dietary changes, etc. might've done significantly more.

1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3925973/, from the abstract, "Based on the present literature, unless the overall volume of aerobic ET is very high, clinically significant weight loss is unlikely to occur. "

Well, since I was there, I can say that her diet was mostly unchanged.

I will add that the walks were around an hour to two to get 10k steps and over 4 miles.

I challenge anyone to walk an extra ~25 miles a week with no diet change to see if they gain weight.

Depending on fitness level (cardio, muscle strength, physical weight) walking can very much be strenuous exercise.

Direct caloric burn, long term metabolism changes, etc. for a given activity vary based on the input fitness level of the person.

Calories in is the easiest levee to pull for rapid change as exercising enough for major direct calorie burn is challenging at the beginning. The biggest short term exercise impact is from activities that increase muscle mass as muscle takes calories to maintain thus boosting metabolism.

If you're sedentary, walking is going to boost your heartrate

Weight loss is simply calories in - calories out. If she walked an hour a day and ate the same amount, she was burning around ~300 extra calories a day.

Pretty sure her daily walks did contribute significantly to her weight loss.

Calories in - calories out fails to explain why people consume and expend as many calories as they do. As the series discusses, many calorie sinks such as fidgeting and body temperature are subconscious or autonomic and seem to be used by our bodies to help regulate our weight. And some people clearly have very strong hunger drives.

Clearly something has changed over the past hundred years. Saying that we got richer fails to explain why the rich people of yore, while fat by the standards of their day, are not fat by modern standards. Saying we have gone down hill in terms of sticktoitiveness is not really a verifiable claim and does nothing to offer a solution. So it is absolutely worth further investigating what is going on.

Food scientist do engineer foods to make you want to eat more of it (and not feel full). It is hard to resist processed food technology.

>If she walked an hour a day and ate the same amount

If she does more activity, she gets hungrier. This will pressure more eating. Fighting that is a losing battle for majority of dieters.

Furthermore, consider that the body is a lot more complicated than "calories in, calories out". It can change your hunger level, lower the body temperature, reduce energy spent on fighting disease...

Also, women seem to lose more weight from walking than men do.

(I do apologize as my response was based on a science article that I read not too long ago but I cannot find it to substantiate my claim)

What if the chemicals aren't making you fat directly, but messing with your neurotransmitters and sapping your motivation?

Doesn't seem completely out of the realm of possibility.

That would be an interesting study.

I wonder if one could find an ethical human study that could parse out a molecule and its effect on demotivation compared to the effect of media, sunlight exposure, obesity, etc.

The bloggers are working on designing such a study. The good news is that weight loss studies almost all show small effect sizes so if remove a chemical exposure factor is the solution you would expect the results to be pretty obvious. I mean, if getting rid of PFAS "prevents obesity" but a McDonalds ad undoes the effect, then it was probably the McDonalds ad causing the obesity, not the PFAS. The bad news is that preventing chemical exposure is really hard to do.

This is what the series actually discusses as the most likely possibility. Essentially the idea is that PFAS or lithium could be making you hungry when you don't need to be. Hence the name "a chemical hunger."

People hate exercise so much they prefer expensive diets.

If you don't burn the calories you eat, no matter how few they may be, you will never lose weight.

That’s why I don’t call it exercise anymore.

Literally, it’s walking while reading your email on the phone. Find a beautiful spot in nature, take advantage of local rivers and beaches…

Lack of vitamin D due to low levels of sunlight exposure is very harmful…

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