It's actually very accurate. It's like saying black men commit crimes more than white men and leaving it at that without factoring in history, socioeconomic status, segregation, and a myriad of factors.

The last source I will link you to, while specifically talking about women, clearly shows that socioeconomic status increases likelihood of obesity. If an overwhelmingly amount of people of a race are poor ( http://www.pewresearch.org/fact-tank/2014/12/12/racial-wealth-gaps-great-recession/) then of course they're going to have a higher rate of obesity. I understand it's in part culture and other factors do have an influence but a huge factor is income.

"The idea that food insecurity increases the risk of obesity may seem counterintuitive, but the present study is at least the third to confirm this association. In our study, NHW women who were food insecure without hunger were 36% more likely to be obese than food secure NHW women; women of other race/ethnicities reporting food insecurity without and with hunger had 1.5 and 2.8 times the risk of obesity, respectively, compared to their food secure counterparts. The studies of Olson and Townsend also found intermediate levels of food insecurity to be positively associated with risk for obesity or overweight (3,12). Olson categorized household food insecu- rity according to the Radimer/Cornell measure and found that mean BMI and prevalence of obesity (BMI 􏰃 29 kg/m2) were greater for women from food insecure households compared to women from food secure households. Townsend categorized household food insecurity (mild, moderate or severe) using the USDA food sufficiency indicator, and found that women from households with mild food insecurity were 30% more likely than food secure women to be overweight (BMI 􏰇 27.3 kg/m2)."

http://jn.nutrition.org/content/133/4/1070.full.pdf