Fructose does cause problems just like many other "human foods"; just because you can eat them raw does not mean they are paleo and that means healthy... Perhaps that is why many "go out and get moving" insted of being able to focus on life! Diet will affect our behaviour...
Nicola,
I do not believe that an all carnivorous diet is one that we have evolved on for any length of time as a species. High in animal foods, yes, but not devoid of plant matter. Even the Inuit of recent times before civilization encroached ate fruit in summer and preserved it for winter. When you think about having to depend on your environment for food, you can imagine that choice of foods is/was not always an option. You have to eat to survive, and without farms to supply you, would you really turn down summer fruits because of the fear of some fructose?
Fructose may cause problems in high amounts for some people. But for omnivores eating locally grown foods, I don't think that eating fruit when it is in season is a bad thing for many people. I think some people on this board even eat a good amount of fruit year round without problem. Of course, I would probably not do so well on a great amount of fruit daily, personally. I eat seasonal, summer fruit maybe 5 servings a week perhaps at most. But people here are probably health-conscious enough not to eat high fructose corn syrup (which is what Dr. Groves' diabetes article focused on), table sugar, and other processed foods with lots of sweetener. I don't even eat bananas myself, but some people might enjoy them without problems.
My point is that we can vilify anything and find fault in it, or we can find a moderate approach. We can stress out about the glycogen in muscle meat. We can worry about eating too much fat, too little fat. And I suppose the purpose of this group is to discuss these issues at length. But at what point is it an obsession? Did our ancestors fret about all of this? To some extent perhaps. For instance, when the animals available were lean, the tribe would be concerned about famine, and things we now call rabbit starvation. But again, I don't think these same people, depending on the land and/or sea in their vicinity shunned fruit in season because they worried about fructose. Many fruits are altered to be sweeter in the modern world, but berries, melons, tomatoes, cucumbers, coconut, avocados and many others are not sweet enough in reasonable amounts to fret about and can add nutrients and water to the diet.
And that is another consideration in itself. How to get fresh water in survival situations? It is a great concern. In the desert, there are cacti and small animals with liquid. I would definitely eat the fruit or the plant to hydrate myself when pumped in water was not available.
Second-opinions on fructose:
http://www.second-opinions.co.uk/fructose-diabetes.html