Okay. Lets look at this anecdotally.
I used to cycle a lot of miles and would certainly classify myself as an athlete (when I was younger). Without carbs and large amounts of food (before, during and after the ride), my performance suffered. This actually happened. You NEED carbs to replenish glycogen reserves to use during exercise. The same goes for water, during serious exercise. My endurance rides would typically last 5-6 hours (continuously on the bike).
Lets take a look at the Tour de France cyclists.
After each day, they load up on carbs. They also have injections of vitamins and other potions. Intravenous drips are common, between days. Why? Because if the glycogen reserves are not replenished over night, their performance will seriously degrade as the days wear on. They cannot starve themselves.
Lets take a look at the World strongest men (those guys who enter competitons). These guys need 1000s of calories per day. This huge calorie consumption is common with all the competitors. And to consume these calories they cannot starve themselves at any point in the day. It is this huge calorie ingestion which allows them to maintain their performance and work their muscles at full power.
Now let me give you an example of people who go through sustained starvation through low calories. The best example I can give is what happened in the concentration camps in 1940s. The prisoners were given little food (starvation/fasting) and were made to do manual labour (training). Many prisoners who were exposed to this complained of becoming weak. This is actually a fact.
I've given you 3 examples of athletes performing at their best when fully carbed/fueled. I've given you 1 example of what happens when somebody doesnt eat properly.
Give me a counter argument please...and have fun while breaking down my reasoning
PS. for people posting in this thread, please don't get emotional when replying - this is a public forum and you should expect to read opinions which disagree with your own. If you are getting emotional, then its best to unsubscribe to the thread.