Yeah, I saw that, looks.....lacking.

Sure you can test whether saturated fat makes couples more likely to argue or feel more stress, but unless they are also testing for the other differences between fast food and whatever their control healthy meal is, I doubt the whole thing means much. Using fast food vs. "a healthy meal" isn't really the way I'd go about this, too many variables. Fast food is full of craaaaazy chemicals, people are likely to order a HFCS filled beverage to go with that burger, the fries are full of trans fats and fried in oil with additional silicone additives to keep the oil from foaming. Not to mention, when families resort to fast food, they are likely to already be in the midst of a stressful time-crunched day. I kind of like where I think they are going with this study, to try and steer people towards home cooking, but I doubt their hypothesis is going to hold up unless they don't differentiate between trans fats and saturated fats. In some past studies trans fats have been shown to increase aggression and stress hormones, saturated fat has been shown to reduce it. But you know, the easiest way to get funding for a nutritional study in the last 30 years in the US has been to say you are studying some negative side effect of saturated fat, so I can't really blame them for wanting to stay employed.

I also think it comes across as an annoying blame the victim, "stupid poor people" study, which frankly I've had just about enough of. If we really want to shift people away from relying on fast food for the bulk of their meals we have to a) actually have grocery stores in every neighborhood, and b) restructure society so that the working poor and lower middle class don't have to work 2-4 full time jobs per household just to pay the rent, and rely on fast cheap food because there isn't the time, energy, or funds for healthy food.

My N=1 is that we tend to have the most stressful arguments when we are hungry, and the cure is a nice fatty meal. After sharing a cheese plate, osso bucco, a lovely chunk of meat, and dessert (all high fat foods) we are much more likely to just sit there and smile contentedly at each other, even if we had been quite snippy and arguing before dinner.

If someone served me liver and onions for one meal, and then a plate of steamed vegetables and rice for another meal, I think I'd feel much more argumentative after the latter if only because of the blood sugar dysregulation.