I haven't watched the show, but I do have some thoughts on isolation and on lack of food and the effects it has on your psyche.
I spent a long time as a mountain guide and got to the point that I enjoyed solo climbing more than climbing with partners so I spent quite a bit of time alone for somewhat extended periods of time (probably up to about a month and a half). When I was younger I enjoyed the solitude and liked not having to find a partner with about the same skills as me (so you're either having to carry the burden of the other person or they're having to carry you, as far as skills and physical fitness levels go). As I started to get a little older (mid-20's) I found that I started to long to see other people, which really annoyed me. I continued to climb solo when doing it for fun, but I found I preferred areas where I would likely run into other climbers to break the solitude. I find that after just a few days I start to get lonely. I'm fine for solo weekend trips, but after 5 or 6 days I really want to start hearing other voices and seeing other people. It depressed me a bit because I figured I was perfect for the fantasy solo survival scenario after the apocolypse depending on no one else, just my skills and wits. Good thing I have a family to take care of, I guess. The fact of the matter is, as humans we are social creatures and too much isolation tends to wear on the mind of most people. Some people are probably fine, but most people are not. Spend a few months in the wild by yourself and you come a very changed person, not all of it for the better.
In the military and as a climber I have gone for days at a time without food (always combined with sleep deprivation, which obviously changes the equation for the worse. I suspect this guy on the show wasn't getting much sleep do to stress of the situation and his fears, reality based or not). I've only gone as long as 6 days without food (and have gone 3-4 days without food on many occassions, all while burning at least 8000 colories a day) and I know what effects it had on my body. Burning many more calories than you are taking in has pretty immediate effects on you. You start getting irritated early on, due to low blood sugar, but it only goes down hill from there. Soon you start making bad decisions because the blood from the brain is being shunted to run essential organs (heart, lungs, etc.) that are necessary to survive and to keep up the work that you are demanding from your body. Your body grows weaker and weaker (compounded heavily by lack of oxygen if you are climbing at altitude, which robs your body's ability to deliver food to the muscles and further degrades the thinking process, something referred to as "lizard brain" in the climbing world, as it brings your thinking down to the most primordial, base thinking processes, and everything goes into slow motion). All of this has heavy effects on your emotions, and some people become extremely emotional, which translates into despair or anger in some (from my experience I tend to become quieter and quieter and more isolative so I tend to focus on the next step instead of the big picture to stay focused and to accomplish whatever I have set out to do. With lizard brain, small steps are easier to focus on and accomplish), which of course again effects your decision making processes and can greatly effect group dynamics (to the point that many climbing partnerships are permanently damaged by a bad climbing trip, especially an epic one, often ending friendships).
For short term survival, I intellectually understand that food is not important, but psychologically it's very important for several reasons: food helps to keep your mind clear which aids in decision making, a pain-hungry stomach is a huge and difficult distraction to ignore making the situation seem worse than it is, and getting food helps distract me from feeling hopelessness or despair and to stay focused which is an important aspect of who survives and who dies. It doesn't always have to expend tons of energy to get food. Eating insects for example, which has a great energy output for little energy expenditure, and I don't mind bugs having eaten them often in my travels.
I have been in several short term survival situations and even if I had food I still spent time getting more food, as you never know when a short term emergency will turn into a long term one. I have respect for Les Stroud for his willingness and his ability to go a week at a time without food. I know what effects it has on me, and I avoid it at all costs.
It's a worthwhile experiment to go several days without food or sleep or alone while performing heavy and difficult tasks. It will show you how you are effected by these variables, which may change your thinking on survival, which priorities are highest, and what gear you should bring or know how to prepare in the wild. You may expose weaknesses you were unaware of, which you may be able to improve in safer and less stressful environments. After experiencing these things for real, you may not like what you learn about yourself, but you'll be better for it.