Skim milk = Skinny?

December 11, 2006 8:52 PM

A lot of the studies I've googled indicate that there is a non-intuitive relationship between skim milk and obesity, at least in children. Does this extend to adults? Could someone explain how whole milk makes you lose weight?
posted by anotherpanacea to health & fitness (11 comments total)

Maybe because it's more filling?

I've recently been eating a big bowl of whole milk yogurt with a tablespoon of flax seed oil stirred in, on top of my regular breakfast (oatmeal or eggs or cereal and soy milk), and I find that I pretty much don't feel the urge to snack for close to six hours now that I've upped by caloric intake with filling foods. I've added about 250 calories to my breakfast, but by not snacking I'm probably cutting 350 to 400 calories from my later-in-the-day munching. That's a reduction of 100 to 150 calories.

Assuming you're at equilibrium before you reduce your overall caloric intake, you're likely to lose weight if filling foods inspire you to take in fewer calories overall.
posted by croutonsupafreak at 9:12 PM on December 11, 2006

1) Correlation doesn't = causation. Perhaps parents give their overweight children skim milk thinking that it's healthy and will result in weight loss, or at least prevent weight gain due to the fat and calories in normal milk. Think about it -- if you had an average weight kid with no weight problems at all, you probably wouldn't be foisting skim milk on her. If the kid started gaining weight, though, maybe you'd think about switching her to skim. In fact, if there is some sort of causal effect here, it could be that being overweight causes you to drink skim. Not the other way around...

2) Like croutonsupafreak says, fat is filling. As the fat to sugar ratio decreases, the likelihood of feeling full decreases, as does the amount of time until you're hungry again. Hence drinking whole milk will probably result in your eating less overall, which could compensate for the higher number of calories in whole milk.
posted by sentient at 9:32 PM on December 11, 2006

There's the "Atkins Diet" theory that says that fat in the diet has nothing to do with weight gain/loss. The problem is too many carbos, according to that theory.
posted by Steven C. Den Beste at 9:47 PM on December 11, 2006

There is a large problem of (possibly) fat parents who don't want fat kids so they put them on diets from day 1.

Such kids are given low fat foods and are always prevented from eating as much as they want. Being given extra food can be used as a treat weapon.

Once kids can get their own food (e.g. from stores) they rebel, discover new taste sensations, go overboard, and blimp up.

I think the correlation is more between kids being put on diets rather than skim-milk per say.
posted by MonkeySaltedNuts at 9:56 PM on December 11, 2006

I'm wondering just exactly the nature of the relationship. Are the studies you've read compare skim milk and whole milk in relationship to one another and a control? Or are you reading that children who drink a lot of skim milk are also obese? It could be how the statistics are looked at; I imagine that a milk/obesity question would be researched with a longitudinal study from which casual relationships are hard to determine.

It's probably not causative. A cup of skim milk has less calories than a cup of whole milk... So it would take considerably more skim milk drinking than whole milk drinking to have an impact on weight gain. This tells me that the relationship might be behavioral: why would one drink more skim milk than whole milk?

This could be a combination of many factors, as mentioned above. Skim milk could be percieved as healthier and thus consumed in greater quantity than whole milk. Or maybe kids find the taste of whole milk too strange. Or maybe the caloric content of skim milk is supplemented by extra sugary cereal to make it taste better.

I'm going to go with: because they are percieved as being healthier, low fat foods are consumed in levels that equal or surpass their non-low fat food counterparts calorie-wise.

Could you provide links to the studies you have read?
posted by Mister Cheese at 10:06 PM on December 11, 2006

Milk is actually pretty bad for you either way.

Shouldn't the studies which are claiming this relationship be showing the relationship?
posted by jesirose at 10:09 PM on December 11, 2006

I'm going to go with: because they are percieved as being healthier, low fat foods are consumed in levels that equal or surpass their non-low fat food counterparts calorie-wise.
I agree. I personally think that liquid calories are a big part of the obesity epidemic. It does not really matter in that regard whether you are drinking juice, soda or skim milk. A cup of skim milk still has 86 calories. A cup of water or tea has none. Two cups of skim milk a day do add up.
posted by davar at 2:31 AM on December 12, 2006

At the same time, there are also studies out there linking weight loss to the addition of skim or low fat milk to your diet. The same way that there are many many studies saying that milk is great for you, and many studies saying that milk is horrible for you. You have to take these things with a grain of salt. Especially if you're finding them on the internet (unless you're specifically seeing them in online versions of reputable scientific sources).
posted by antifuse at 2:46 AM on December 12, 2006

There's this NYTimes article, which is very careful about showing that skim milk doesn't make kids thin, but making no broader claims.

"Drinking milk can make kids fat — and surprisingly, skim milk is more of a culprit than whole milk."

Drinking Low-Fat Pasteurized Milk Triggers Obesity

Part of the problem here is that there don't seem to be a lot of studies, but "experts" are drawing vastly different conclusions from this paucity of data. I'm just trying to figure out if we should switch to whole milk or 2%, since we've always drunk skim milk. But I'm not finding the authoritative source or the explanations I was hoping for. Thanks for the answers so far!
posted by anotherpanacea at 5:39 AM on December 12, 2006

Part of it has to do with what the previous posters has said. I would also like to add that when the fat intake goes down, the body perceives a "starvation period" and begins to hang onto calories. So by only eating low fat products, the body may actually hang onto the fat that's there "tighter" than if regular products are comsumed. I think the key to healthy weight loss is not to change the products eaten but rather decrease the portions and up the activity level. This is my two cents, FWIW.
posted by LunaticFringe at 6:21 AM on December 12, 2006

In breastfeeding, babies are hungrier, and hungry more often, when they do not nurse long enough or forcefully enough to completely empty the breast. This is because as the breast empties, the first milk, called the foremilk, has a lower fat content than the "hindmilk" which comes last in the process. (The fat collects in the milk ducts and clumps together and comes out in greater quantities with the end of the milk, like the leaves collect in clumps in the teapot and will come out when the last cup is poured.) The thinner and more watery foremilk satisfies thirst and hydration needs very well but the richer, fattier, higher-calorie hindmilk is more filling and satisfies hunger.

It makes me wonder if regularly consuming quantities of lowfat cow milk doesn't trip an internal switch (which would otherwise be dormant post-weaning) making the body think that no hindmilk is being consumed which means something is wrong. That could trigger both additional hunger signals and higher caloric consumption as well as the "oops, I'm starving" signal and the conservation of calories, which would combine to lead to weight gain.
posted by Dreama at 8:21 AM on December 12, 2006 [1 favorite]