If you’ve been thinking about going on a diet soon, you now have extra incentive coming from your pocketbook: Food prices at the grocery store are going up at the fastest rates since 2003.

And since it’s hard to do without sustenance, that means other economic sectors will get short-changed:

Escalating food costs could present a greater problem than soaring oil prices for the national economy because the average household spends three times as much for food as for gasoline. Food accounts for about 13 percent of household spending, compared with about 4 percent for gas.

And consumers spending more on food have less disposable income to spend on items that keep retailers happy – from electronics to dining out. Food prices are rising while home values fall and the stock market falters – all of which can shake consumer confidence.

Maybe it’ll turn out cheaper to start eating and drinking petroleum products…