And insulin resistance is an issue if you're overweight. For a normal person it's a non-issue.
And, regarding "for a normal person it's a non-issue" – How do you think those overweight people got overweight? I was once at a healthy weight, but my terrible diet got me where I am today. If I'd eaten differently, I wouldn't be in this mess to begin with.
68.5% of the US adult population is overweight [1], so even if it was only a problem for overweight people, in the US at least, overweight is normal. ("Normal" and "ideal" aren't the same thing.)
[1] Ogden C. L., Carroll, M. D., Kit, B.K., & Flegal K. M. (2014). Prevalence of childhood and adult obesity in the United States, 2011-2012. Journal of the American Medical Association, 311(8), 806-814.