In support of this view, it was recently shown that HFD increases the risk and severity of non-allergic asthma due to a heightened Th17/IL-17 response [26], which might explain why obesity (commonly as a result of increased fat consumption in the diet) in humans consistently increases the risk of developing non-allergic asthma [3,4], while the correlation with allergic asthma is tenuous [5,6]. This evidence concerns the gene IL17A and allergic asthma.