According to recent information (2016 data being the most “recent”), Farmers receive 14.8¢ of every food dollar spent on domestically produced food. This is down from 15.6¢ in 2015 and 17.2¢ in 2014, and is the lowest since the series was launched in 1993. There are other statistics which pull out data including “food consumed at home” versus “food consumed away from home.”
Costs of farming continue to rise, cost of required investment into farming continues to rise (equipment being a major factor), and small and marginal farmers will continue to be edged out of the industry (unless they can find a place in a desirable and more profitable niche).
The largest piece of the food dollar pie belongs to non-farm marketing and transportation. Food Services includes restaurant and institutional costs.
For more information (and more handy charts) check out the USDA page on Food Prices and Spending.