Bill O’Reilly of Fox News doesn’t restrict his passions to matters of politics, race, class, taxes and free stuff. He also talks nutrition, as in the “Fox & Friends” episode in which the popular host attacked wheat.

Just last night, O’Reilly reprised a nutrition tip that could come in handy around the holidays: “Drinking a glass of water with lemon juice 30 minutes before you eat a meal: If you do that, you’ll be far less hungry and perhaps you won’t eat as much.”

Good stuff or quackery? The former, it would appear. Diet expert Susan Mitchell says:

Actually the concept does have merit and is used by many dietitians as a weight loss tip. I actually tell people to drink 1-2 glasses of water before a meal . . . 8-16 ounces. It’s all about the volume and the volume of water helping to fill one up so that they potentially eat less. The water can be plain or lemon/lime/orange added for flavor.

And Jo-Ann Heslin of NRH Nutrition Consultants, Inc.:

My best guess is that the lemon juice does little [more] than add taste to the water to make it more palatable, but drinking a large glass of water before a meal is an old dieting trick to fill up the stomach and make you feel less hungry for food. It does work, but you might feel more hungry later because the interval between meals could be shortened due to eating a smaller meal. The post-meal response would be variable depending on what you ate and how much.