Dear Student, While going above the trophic level we should keep in mind that energy is lost at each trophic level and also the concept of Biomagnification that states that concentration of any harmful chemical is increased at higher trophic levels. So, after considering both, we come to a conclusion that smaller the food chain, better is the food chain. So, a food chain with 2-3 trophic levels is better than that with 4-5 trophic levels. Regards