Overweight by BMI has been found in many studies to have the lowest mortality rate, especially in older populations.
I don’t remember if I made this up when being silly one night, or if I read/heard something about it as a real study…but having a thicker layer of “me” around my organs in my midsection could save them from puncture if stabbed by a blade or other implement short enough.
As in - you might not be able to nick any of my organs from my front with a paring knife or a pocket knife, but it could be a very deadly proposition for a thin person.
The flip side though, is that a surgeon has a more difficult time if they need to open your abdomen. Recovery is more difficult as well.
Two words:
Sumo wrestlers.
Cite?
Since this is GQ, I’d love to see a cite for this ('cause I don’t believe it).
Similar to the OP’s first case about famines but a little more realistic and everyday, I understand it is better for older people to carry a few extra pounds (maybe 10 or 20) so that it will be easier for them to survive a bout of pneumonia. Pneumonia is often a side effect of any hospital stay, and if your body has no extra resources to draw on it can put you at greater risk of death from that (rather than from whatever brought you to the hospital in the first place).
Seems like a closed, self-reinforcing loop, too 
Been fat, been less fat, and been normal. The only useful thing being heavier was good for was shifting loads while moving using your body weight, beyond that it’s all pretty much a huge negative.
There is more to love.
As to the references about fat protecting you from injury, it’s been my experience as an ED physician that obese patients are much more difficult to evaluate for both medical and surgical problems.
And I don’t think being fat helps you avoid injury in a fall. In fact, there’s more stress on the musculoskeletal system when you go down, and if you are really fat I think you are more likely to fall in the first place b/c it’s tougher to see where you are going.
There was a brief time (1991) when I was at or even under my ideal weight as an adult. One odd thing I remember was that my fingers felt like they moved a little quicker. It was as thought my fingers had lost a little weight themselves!
Even though I was underweight, I STILL had a belly sticking out. My physiology absolutely LOVES to concentrate most of my fat in my abdomen. Even when the total amount of body fat I’m carrying is on the low end of what’s still considered healthy, a heck of a lot of that fat was still visceral fat. Bah. Stupid body.
More cushion for the pushin’.
… You can survive a longer famine without getting malnutrition (there’s vitamins in the fat too. See "how do eskimo’s live without getting scurvy? " The question should really about malnutrition in general …)
With respect to Eskimos and scurvy, there may be vitamins in fat, but I’d be surprised if there was much vitamin C there (i.e. vitamin C is not fat soluble so it wouldn’t be stored in fat tissue unlike, say, vitamin D).
Being overweight has some health benefits in that the death rate is lower. The reason, I do not know. I’ve heard a potential cause includes that overweight people have more lean tissue and muscle mass to both cushion them from accidents and help them get through illnesses. When people gain weight it isn’t like it is all fat, for roughly every 2-3 pounds of fat you gain you gain 1 lb of lean tissue to carry it around.
Also if you get really, really, really fat they’ll give you a show on TLC.
When a fat person gets into a fight, they just have to stand on someone’s head and that person will suffer a skull fracture and quickly die.
You don’t have to know a lot about fighting if you can just get on top of someone and then put your weight on their skull.
This was probably covered already, but in an overweight body, if the famine comes I will live
Plus there is more of a natural intimidation factor with big guys. 
This is good for preventing violence. If you actually DO get into a fight, you will have advantages too. You have a natural buffer against (some) stomach strikes as well as more mass to add power to your strikes. If you get your opponent to the floor, the fight can be over if you piledrive all your weight onto them or if you just want to pin them down. (Possibly) woman can feel safer around you because of that (like you can protect them better). Some women and men prefer larger partners so this can get your foot in the door in and of itself (apart from feeling safer)
I think that being overweight also naturally builds up your leg muscles because you have more to carry. That’s not always the case especially if someone is SUPER sedentary.
Plus if you like being a lineman, on the football field you’re more likely to get that gig, as well as qualify more for a sumo competition. You can probably do better cannon balls then other people too. Some movie rolls are particularly for larger people, so if acting is your thing this can be a plus. You are generally going to be more likely to be chosen for a security or doorman job as well.
Also, since you are often perceived as less attractive (or at least you may THINK you are) you may try harder to work on your people skills, your intelligence, etc. You will have more drive to actually develop some skills rather than just skating by off of (at least what society may think are) good looks. You won’t (necessarily) be so quick to discount another person on the basis of if they fit into what society thinks is proper, and (may) also come to know what it is in life to be viewed poorly so you develop more understanding. You may be less critical of people because you (have probably) struggled ineffectively to lose weight so you know what that sort of thing is like… this can lead to more understanding and acceptance.
Also you get cold less, fat acts as a natural insulator.
Extra space for tattoos?
I’ve seen really huge guys outside in frigid weather wearing a t-shirt and jeans. But what happens in July when it’s 90 degrees and humid?
You know someone hitting on you isn’t just in it for your looks.
Accepting a fat lifestyle, you can eat whatever and lay around all you want, guilt free!
You might have a shorter lifespan, sure, but you’ll be in bliss until the bitter end.