Hmm, the guy has a point though over-weight people tend to have poor immune system due to there diet. I think people are just complain to much, and like you say go into GP clinics with flu, and colds wasting the time of are doctors.
It's not so easily linked to diet, it's linked to bone marrow content vs the size of the body. Someone who is chronically obese needs vastly more immune cells (leukocytes, lymphocytes, macrophages, mast and dendritic cells ect). Illnesses gained from being overweight like diabetes can contribute to a poorer immune system due to hardening and narrowing of capillaries, which stop or hinder white blood cells from travelling through the HEV component of a capillary.



its all those mcdonalds and kfcs making you immune 
