If by food calorie analysis you mean bomb calorimetry, it will depend on the food. Foods containing high levels of dietary fibre will often give higher values by bomb calorimetry than by calculation from the food nutrients (assuming the carbohydrate has been measured rather than by difference).

There is a more sofisticated method used by the USDA to measure actual calorie content, which has been used for almonds, pistachios (and walnuts). Which show the calculated values are often wrong also.

http://www.ncbi.nlm.nih.gov/pubmed/21733319 pistachio

http://ajcn.nutrition.org/content/96/2/296.abstract almond

If the food pattern is non-vegetarian like- fried chicken (contains only slight amount of spices and oil), Egg omelette(contains only slight amount of spices and oil), toasted bread with butter(Bread edges has been removed), Tofu n cheese balls, Whole milk (200mL milk+10g sugar), Potato cutlet(Boiled potato+spices+oil).

These foods does not contain any fibre/very slight amount of fibre may be present. but the values are almost 150-200 K.cals With increased difference are getting.

Are you actually measuring the nutrient content of the foods as eaten? And using food tables to compare with? Is the difference of 150-200 kcals higher for the actual food, or from the tables?

If oil is present in the food it can affect in vivo digestibility by presenting a barrier to digestive enzymes. High fat foods may need to be defatted before further nutrient testing because the fat can interfere.

Also the foods you are talking about may not contain fibre, but some components may not be 100% digestible. http://www.ncbi.nlm.nih.gov/pubmed/24436037

Not sure about your question. Do you mean via bomb calorimeter? I tested over 30 ready made supermarket meals, and while their labelling was clearly done via Atwater, all but two were over. 48% of the samples exceeded 20% positive tolerance (kcal/100gr) and the highest was 36.69% over stated.

Or do you want to measure actual intake (including collection faeces)? It depends then on the mix of ingested food and the way they are prepared.

Dear Terri, i have calculated the nutritive values from the NIN book,(National Institute of Nutrition). 

As per earlier discussions, in chicken, carbohydrates are present as white meat but what about the egg? Does hen egg contains any carbohydrates? please clarify...,