It appears that having 20 to 30 extra pounds provides some extra protection against illness and can help you recover from injuries and infections.
Does this mean that you should try to gain weight or to eat unhealthy? No, of course not! What it does show is that there is some exaggeration in the aforementioned health crisis involving those who are overweight. Everyone should do their best to eat a nutritious diet focusing on foods that make them feel great. Everyone should move to the best of their ability. The benefits of a healthy diet and regular exercise are well proven. What we shouldn't do is worry about our weight. What we shouldn't do is judge others for the shape of their bodies. What we shouldn't do is fail at doing what is best for us because of an obsession with reaching a size or shape that is not only perhaps unattainable but also may be unhealthier than the shape that we naturally fall into!