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Milk: It does a body good, right? Maybe not as much as we thought.

Despite what those milk-mustachioed celebrities in those "Got Milk?" ads have been telling us for years, humans have no nutritional requirement for milk, and it may be doing us more harm than good because of all the sugar even plain non-fat milk contains, according to a new study by a Harvard professor.

In the paper published in the Journal of the American Medical Association Pediatrics, Harvard pediatrician David Ludwig notes that there's been a lot of research linking sugar-sweetened beverages to obesity, but a surprising lack of data comparing the health effects of reduced-fat milk to whole milk.

Ludwig argues that we should question what we've been taught about drinking that recommended three cups a day and that lower-fat milk is really no better than full-fat milk. Low-fat milk, he argues, doesn't fill you up as much and people end gaining weight by drinking more of it or reaching for that extra chocolate-chip cookie. Though he says the worst culprits, especially for children, are the sweetened varieties like chocolate milk, which of course most kids prefer.

"The substitution of sweetened reduced-fat milk for unsweetened whole milk — which lowers saturated fat by 3 g but increases sugar by 13 g per cup — clearly undermines diet quality, especially in a population with excessive sugar consumption," says Ludwig.

Evidently, drinking milk in general is not even as good for our bones as we thought. Ludwig points out that bone fracture rates tend to be lower in countries that do not consume milk, compared with those that do — while there are many other sources of calcium.

However, people probably shouldn't be too quick to be deleting dairy from their diets just yet. The Globe and Mail presented the study to its in-house dietitian Leslie Beck, who pointed out that the sugar in plain milk — 11 grams of sugar in a tiny carton of fat-free milk — is naturally occurring lactose and should not be cause for alarm.

Besides, says Beck, it's a lot easier to get kids to drink milk for their daily calcium needs than it is for them to eat up their collard greens, and parents should be a lot more worried about the real junk food kids are eatings these days.

The Harvard study's findings also shouldn't come as too much a shocker. For ages, the anti-dairy movement, back by nutritionists, vegans and vocal Hollywood A-listers like Gywneth Paltrow alike, has been saying that sure milk is nature's perfect food...if you're a calf.

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