It is known that the bacteria that produce high amount of butyrate are beneficial, e.g. by decreasing the risk of colon cancer, but this does not seem sufficient to explain the increase in muscle strength that seems to be caused by this species alone.
The study has first found in humans a correlation between muscle strength and the presence of this bacterium. Then they have attempted to determine whether this correlation is due to a causal relationship by killing the gut bacteria in mice, then feeding them with this kind of human gut bacteria. The result was an increased muscle strength, which seems to confirm causality.
How the bacteria increase muscle strength remains unknown. I think that a possible explanation may be that this bacterium produces some substance that mimics a human hormone, e.g. a steroid, in which case it would be a kind of natural doping.
It can be, but it's often not. The thing that makes hamburgers harmful isn't really the "chemicals" or processing or whatever, it's the fact that it's red meat with high amounts of saturated fat.
You would have to use low fat beef, and ideally not beef but turkey.
I think some people think that burgers, fries, steak, and milkshakes are bad for you because they're fast food or restaurant food. No... no that stuff is just bad for you. You'll get a heart attack if you make it at home, too. Just eat it in moderation and eat more vegetables.
IMHO it's the restaurant. For a variety of reasons but here's just one example of a mechanic:
> Repeatedly heated cooking oils (RCO) can generate varieties of compounds, including polycyclic aromatic hydrocarbons (PAH), some of which have been reported as carcinogenic. RCO is one of the commonly consumed cooking and frying medium. These RCO consumption and inhalation of cooking fumes can pose a serious health hazard.
Nutrition is complicated and rules of thumb can be really useful even if they sometimes over simplify things. One good rule that has had a ton of research interest into it in the past decade or so is ultra-processed foods. Here's a BMJ review
> Greater exposure to ultra-processed food was associated with a higher risk of adverse health outcomes, especially cardiometabolic, common mental disorder, and mortality outcomes. These findings provide a rationale to develop and evaluate the effectiveness of using population based and public health measures to target and reduce dietary exposure to ultra-processed foods for improved human health. They also inform and provide support for urgent mechanistic research.
"chemicals" (however those are defined) are bad for you, but unhealthy food is still unhealthy even if it's natural. The naturalism fallacy is just that, a fallacy.
Hamburgers aren't bad because chemicals. They're bad mostly because they're super high in calories, saturated fat, and red meat. All of those are going to contribute to heart disease, metabolic syndrome, diabetes, obesity, etc.
UPF are bad for you, yes. Not necessarily because of the processing, but rather because MOST UPF is unhealthy. That does not mean that non-UPF is magically healthy.
If you deconstruct an UPF and eat it's components, it's still unhealthy. Oreos are bad for you because it's sugar and empty calories. Not because they were made in a factory. If you just take a spoonful of sugar and eat that, that's still bad for you.
I agree that rules of thumb can be good. Here's a simple one:
There are many poisons in nature. Saponins and tannins are extremely poisonous but because they are so widespread in plants and because humans have been eating such a wide variety of plants for so long we've adapted specific pathways to make them basically harmless in standard amounts (some even have medicinal importance). Give those substances to a carnivorous animal and they will suffer or die. Alcohol too is something we've uniquely adapted to. How "poisonous" something is is often a function of how widespread it is. The most lethal poisons are also some of the rarest in nature.
Given the option of two substances, one which we've had 10k years to adapt to and one which was just created in a lab and has structures not like anything commonly found in nature, there is definitely a lower chance that the "natural" substance will be more harmful to you.
It's not that bad for you, but it's definitely not good for you. It's not a very good source of protein and it's fairly calorie dense. It can also be quite high in saturated fat and red meat is a carcinogenic.
Obviously eating steak in moderation is fine. Eating steak everyday is not going to be good for you.
All fiber-consuming gut bacteria, yes - but that's basically synonymous with "good"/beneficial gut bacteria, so it's good advice even if it doesn't give people the massive gainz they might have been hoping for.
