Definition. The host (also called the susceptible host) is the human body: someone who is at the risk of infection. Infections do not necessarily occur when pathogens enter the body of the person whose immune system is functioning normally.Whether or not a pathogen will result in infection depends upon several factors related to the host (the person exposed), the pathogen itself, and the environment.nfections do not necessarily occur when pathogens enter the body of the person whose immune system is functioning normally. Whether or not a pathogen will result in infection depends upon several factors related to the host (the person exposed), the pathogen itself, and the environment.
You can find out how many calories are in a food by looking at the nutrition facts label. The label also will describe the components of the food â how many grams of carbohydrate, protein, and fat it contains. Here's how many calories are in 1 gram of each: 1  carbohydrate â 4 calories.  protein â 4 calories.
Carbs provide 4 calories per gram. Therefore, if youâre consuming 1,600 calories a day aim for 180 to 260 grams of carbs, if you eat 2,000 calories a day shoot for 225 to 325 grams and if you consume 2,400 calories aim for 270 to 390 grams of carbs each day.