I am an analytical chemist who understands a lot about these estimations in food industry or in environment or in the medicine or anywhere. There is nobody to control all these because most of the national nutrition associations work closely with the food industry.

I furnish you some of the values which give you some important information. Potatoes had in 1978, 87 calories/100g, but it was 68 calories in 1990, carrots 1978, 35 calories and in 1990 only 24. Ragi, in 1978, 240 calories and in 1990 only 194 and avocado, 240 in 1978 and in 1990, 205 calories, if we measure now it may be also different.

It can be because of modern analytical methods or the allowed fluctuations in the measurements. With standard deviations and variation coefficients the allowed ranges are measured where 72 is equal to 98 or vice versa.

There are several other factors which influence the calorie valus. How ripe are the vegetables or fruits during harvest. The bananas are not even half ripe when they are harvested in South America. In Europe we add acetylene so that it ripes in the lorry with the necessary temperature. It is different if the lorry has to travel 200 or 800 km.

Think of our raw mangos and the hot stone or calcium carbide.

Moreover carbohydrates mean simple sugar to very complecated starch molecules with numerous sugar molecules. Till date there are no satisfactory methods to estimate all. In food, protein and fat are estimated and from that the carbohydrate values are calculated.

Another big unknown factor is what is happening in our stomach and intestine. Not verything are digested or absorbed to blood. The calories which are coming out must also be measured. This could be never right because the bacteria in our intestine system also consumes or destroys.

Counting calories can make one desperate because what you count is always not correct. I knew many who had permanent stress counting their unending calories and at the end put on more weight before.

Consider the amount and it is easy to calculate and the success is almost pre-planned.