Comment by Merrill | Hacker News Reader

Comment by Merrill | Hacker News Reader

From the PLOS paper >To assist in complying with diet recommendations, participants in the diet change group each received a small hamper of food items including olive oil (Cobram Estate), natural nut butter (Mayvers), nuts and seeds (walnuts, almonds, pepitas, sunflower seeds) and spices (cinnamon, turmeric). They were told to keep their shopping receipts in order to receive a $60 gift card as reimbursement for study foods. Participants in the diet change group also received a brief, 5-minute phone call on Day 7, Day 14 to ask if they were having any difficulties adhering to the diet and troubleshoot problems with reference to the prescribed handouts. Participants in the habitual diet group were given no instructions regarding diet, and were simply asked to return after 3 weeks for follow up. https://journals.plos.org/plosone/article?id=10.1371/journal...

So if you enroll subjects in a study, give them attention, free food, gift card, phone calls, etc. then after three weeks they will feel less depressed than a group of subjects for which nothing was done.

It would be more convincing if they had a third group that they fed blue cheese bacon cheeseburgers, french fries, diet Coke and Lil Debbie cakes from a convenience store. I'd bet even money that the third group would have been less depressed too.

Or even a control group to whom you offered gift cards for things other than food, phone calls etc.

Though I agree with you, sounds suspiciously like the group who was depressed became less depressed as they felt someone cared about them.

That doesn't really account for the difference in like causing more or less happiness.

There’s good evidence that being in social situations, even with complete strangers, and even when you are very introverted and hate doing it, improves your overall happiness.

Great point! I bet the junk food group will still feel better (less depressed) than the group being left alone, unless they were somehow constantly being reminded about the "bad quality" of the food they were eating. It's all about long-term vs short-term state of mind. And three weeks is just too short.

>t's all about long-term vs short-term state of mind.

I think the point is the "state of mind" is a product of everything else going on in the body. It will be infinitely more difficult to have a positive state of mind while your body is contending with chronic inflammation and your unhealthy gut isn't producing serotonin. Your right 3 weeks isn't enough, but biomarkers can be dramatically improved in 3 weeks with change of diet, especially with respect to chronic inflammation.

They did a 3-month followup: >Of the 33 individuals who were able to be contacted, 7 (21.2%) said they had maintained the diet, 19 (57.6%) reported they had maintained some aspects of the diet and 7 (21.2%) reported they had not maintained the diet. There was no difference in depression outcomes between these 3 groups (chi-square >.05).

They don't seem to have done the 3-month follow up with the control group.

It's super tiny group anyway - the experiment is highly underpowered even if they did check control group.

Most importantly it is not a cross design, and even that would need in excess of hundred patients to be meaningful. As is they can be measuring the effect of attention and any kind of change on depression, given some genetic, phenotypical or environmental susceptibilities incidentally found in their treatment group.

Meaning the conclusion is not possible to generalize.

These tiny studies, especially of low quality and poor design are an annoying waste of time and money.

Argument can be made that the mind can change the body just as the body can change the mind. But yes, the notion that "state of mind is a product of everything else going on in the body" does make it easier for empirical studies.

A blue cheese bacon cheeseburger isn't necessarily "junk food". It can actually be pretty nutritious, depending on the specific ingredients.

Its amazing how well the sugar industry has ingrained the 'fat is bad, mmkay?' attitude into society.

Actually I didn't carefully read the list of food the op proposed. I just assumed it made better sense for the op to list junk food. To me, junk food is any highly processed food. I have nothing against fat or glucose.

It's not the fat that makes a blue cheese burger terrible for you. It's the combination of animal fat with refined carbohydrates. Wrap that bad boy in a collard green and you've got yourself a healthy meal.

neither fats nor carbs are bad, as long as you get good quality fats and good quality carbs. The problem is people eat bad quality carbs (highly processed) and they eat way too much fat, especially saturated fat. The scientists from the early studies had it right that too much saturated fats are bad for you. that doesn't mean you need to get rid of all fats. It's not commonly known, but important to remember, there's fat already in fruits, veggies, whole grains already in the correct quantities. Having a few nuts and seeds is also fine. Just be careful with all the processed fats and meats/dairy: you really want to limit those.

You’re saying one should especially limit meat? That’s definitely not the consensus among experts.

The problem is highly processed meats, not necessarily meat in general.

A McDonald's hamburger is a good example of "meat" that would be good to limit.

There's widespread consensus on limiting red meat. Red meat is a class 2 carcinogen ~ that's pretty bad. Processed meat is a class 1 carcinogen, right up there with plutonium and asbestos ~ egregiously bad.

As for other meats and dairy(which is just milk), most serious nutritional researchers will tell you to limit those if not nearly eliminate them from your diet. The media is constantly showing pro-meat stuff because the meat and dairy industry keeps funding pro meat research. It's especially confusing because even some of the largest companies/organization like the AHA and American cancer society is taking money from big meat and big dairy and funding pro dairy/meat research.

The issue is not about an ingredient, but indeed general food.

You can eat junk food filled with carbs (Standard white bread, pure pasta, white rice), likewise junk food full of fats. (Most milk products, highly processed meat.)

The main problem is when the diet is either lacking in things we do not completely understand (vitamins, micronutrients, perhaps phytonutrients) or is effective caloric surplus - that is, you gain weight.

Considering food x as carbs or y as fats or z as protein is reductive to the extreme not warranted by current state of knowledge and leads to milk powder and mashed potato diet. ;)

The basic nutrients do not have a quality other than perhaps the ease with which they're absorbed, which early matters for even somewhat unhealthy person, only perhaps for really sick people.

I wish I could vote you up more than once.

Our knowledge of more than coarse grained dietary needs and effects is grossly overestimated. That vacuum is exploited by commercial interests that typically vilify any form of consumption moderation, and focus instead on promoting one (over)consumption pattern over another.

"Eat lots of different things in moderation because honestly we do not know in enough detail what we need" is sound advice, but sadly just benefits the "patient" and not some profit maximizing economic lobby group.

I have to agree this was done really poorly. Another example of why randomized controlled trials aren't always what they're cracked up to be.

Not sure if a junk food diet would fly, but they could have at least given both groups a gift card and some gifts (maybe the control could have received non-food items of equal value?) and had the same phone calls, but with some "neutral" questions in the no diet change group.

There are plenty of studies that do behavioral controls. Not sure why they didn't do it in this one. Especially when there's a large literature on waitlisting effects on depression (basically people who are waitlisted as opposed to assigned to a behavioral control tend to have the worst outcomes).

>I'd bet even money that the third group would have been less depressed too.

Maybe, but certainly their biomarkers would continue to show chronic (dietary) inflammation and otherwise they would have no improvement in seratonin production in the gut.

Which is important why?

Please support this point by citing or conducting studies of good quality showing causation of these markers on mortality and morbidity endpoints, instead of supposition that it is true.

This is very hard to actually show, by the way.

Hmm, yeah. If I'm sufficiently depressed, things like diet become very negligible. Sense of belonging is much, much more important. I don't recall if anyone ever did a study for that in particular.

While that diet of blue cheese bacon cheeseburgers and Lil Debbie cakes sounds great, I would be pretty miserable on day 2 as a lactose-intolerant person! Although day 1 would be glorious...

Reinforces two of my top rules on food: ignore results and advice

- less than five years old, or

- from Americans

While I might reject some false positives, these rules are easy to implement and improve the signal to noise ratio tremendously.

And the Australians who did the study? Are they just like Americans but even monolingualier?

I think you actually have the kernel of a good heuristic there, but I'd, uh, refine it a bit.

That's funny advice about America. We are undeniably the most obese country.

But I'm hoping that the unique pressure we have placed on ourselves eventually leads us to develop diet solutions that help the whole world.

But as test subjects in an extreme obesity study, the rest of the world is probably wise to avoid American "solutions" to problems they might not even have yet. For example Butter Coffee is a huge improvement for some people here, because it is better than eating a bowl of sugar cereal or having donuts and a Frappacino. But is the Butter Coffee better than a typical Italian breakfast of "Espresso and maybe a small yogurt"?

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