The claim that Sauria's leading nutritional experts' conclusion that a diet high in complex carbohydrates and low in fat is optimal for good health is wrong seems somewhat reasonable at the first glance. After all, the arguer does offer some relevant evidence, and the assumptions weakening this argument are not without any merit. However, three important concerns he/she fails to take into account may undermine the argument seriously.
In the first place, lacking more specific information about the health conditions and living ages of the ancient Saurian people, it is impossible to make an informed conclusion. As it mentioned, the mummified remains of Sauria's ruling classes show the existence of many medical problems, maybe the ruling classes -- the privileged class had more precious food to enjoy, so their diet were not made up of some high-carbohydrate food ,and wee even rich in fat. The mere fact is insufficient evidence to conclude that the general health conditions of common people were bad.
In the second place, the arguer fails to completely and comprehensively consider the reasons which might lead to the medical problems of ancient Sauria. He/she ignores other factors--such as the quality of environment including air and drinking-water, genetic disease, and the relationship among neighborhood --which might be more important in determining one's health and longevity. Any of the above scenarios, if true, would render this analysis a completely presumptuous one.
What further weakens the argument is the arguer unfairly assumes the same diet way--like the ancient Sauria, will lead to the same result in present period. Granted low-fat and high-carbohydrate diets did result in the medical problems among the ancient Saurian, there is no enough and credible evidence to support they will result in the same consequence.
As it stands, the argument suffers from three critical flaws. To strengthen it, the arguer would have to demonstrate that the low-fat and high-carbohydrate diets did lead to many medical problems among the ancient Saurian. Furthermore, he/she must provide founded and acceptable evidence to rule out all the above-mentioned possibilities that might undermine the argument.