If I make $1,500 a month, and head on down to my local Food Maxx warehouse discount supermarket, spending about $200 for groceries to last the month, that's 13 percent of my income for food. Now if I find a better job and make $3,000 a month, which scenario is more realistic: (a) I spend the same $200 a month at the store, making me now spend 7.5 percent of my income on food; or (b) I decide the newfound money is burning a hole in my pocket, so I make every possible effort to spend $400 a month on food to feed the same number of people, keeping myself at 13 percent on food but spending twice as much?
With that in mind, can you see how it's ludicrous to compare percentages of income spent on food without giving figures for what the average incomes are?