Milk, Soda and Some Very Fuzzy Math

Earlier today I circulated an NPR report on the co-existence of hunger and obesity among the poor.  In that report, it was asked why a cash-strapped parent might give a child soda instead of milk and a representative of a local food pantry commented: “A gallon of milk is $3-something. A bottle of orange soda is 89 cents . . . Do the math.”

I was so pleased to see the milk-soda comparison made in this story; this is something that’s been bugging me every since my earlier post about how the far-right wing Heritage Foundation points to obesity in America as proof that hunger isn’t a real problem.   (These are the same people who snarkily accuse the Obamas of “flip-flopping” because of their simultaneous anti-childhood hunger and anti-childhood obesity efforts.  Yuk, yuk.)

In making their case, one “myth” the Heritage Foundation likes to attack is the fact that poor people often turn to fast food and processed foods because such foods are cheaper, and thus a person can be both food-insecure and obese.  Not true, says the HF!  And then it trots out this little factoid, among others:

“[A]s a source of calories, brand name soft drinks such as Coca-Cola and Pepsi are often more expensive (in terms of calories per dollar) than milk.”

This “fact” about milk and soda is such a favorite of the HF that it was even included  in its recent Congressional testimony submitted in opposition to any increase in funding for childhood nutrition programs.

But ever since I saw this milk/soda comparison, I’ve been wondering:  Could it be true?  Is milk really somehow cheaper than soda, despite the glaring difference in price tags ($2.99 per half gallon (which is almost exactly 2 liters) for milk in my area vs. $1.69 for two liters of soda)?

Now, I’ll say up front that I’m a liberal arts major and a lawyer, and there’s a reason I never went to business school — math is not my strong suit.  But here’s what I was able to figure out:

Using the prices quoted above, two liters of soda costs .03 dollars per ounce and each ounce provides 12 calories.  That means that for one dollar, I get about 396 calories.   Approximately two liters of skim milk, on the other hand, costs .05 dollars per ounce and each ounce provides 10 calories.  So, for one dollar, I get 200 calories.

Hey, wait a minute!  That doesn’t work at all!  On a calorie-per-dollar basis, soda is the hands-down winner. Am I missing something?

You bet I am.  What the HF conveniently forgot to tell Congress, but which is buried in a footnote in their original report, is that it bases its comparison on “the non-sale prices of two-liter bottles of Coca-Cola Classic, Pepsi, and Dr Pepper compared to two-gallon containers of whole milk in six stores in the northern Virginia suburbs of Washington, D.C.”

Whoa there, HF.  What’s up with that?

First, why are you comparing two gallons of milk with two liters of soda, when the actual volume equivalent of two liters of soda is a 1/2 gallon carton of milk?

Second, in a position paper all about combatting obesity, why would you use WHOLE milk as the basis for comparison, when every dietician in America would agree that a person seeking to lose weight shouldn’t be drinking whole milk?

Could it possibly be that this is the only way to make your specious milk-is-cheaper-than-soda claim remotely  plausible?  (Sure enough, when you use whole milk and the price for two gallons, milk “wins.”)

Moreover, what all of these details miss is the fact that it took this over-educated person about twenty minutes to figure out an accurate “calorie per dollar” calculation; the average shopper had better not head off to the market without solid math skills, a calculator, and a whole lot of extra time.

The bottom line is, we’d all like to see poverty-stricken people cook up a nutritious, cheap and filling pot of beans and rice, but maybe that’s not always realistic for a person who lacks education (to know this is the better choice), cooking skills (maybe these weren’t modeled at home), time (working two jobs?) or access to such foods (as when one has to rely on a convenience store for groceries).   The sad truth is, when real people want to get the most filling food for their money in the most convenient way possible, they’re often intuitively drawn to high-fat, dirt cheap items — fast food, candy, soda and the like.

There are arguments to be made against using federal funding to provide food assistance to the poor and I’m fine if the HF wants to make them.  But stop trotting out the “myth-busters” that rest on squirrelly math.


  1. mara says

    Well done Bettina! I’ll be sending my kids to you for help with their math homework in the coming year! So much wrong with the HF claim, including using non sale price, when soda is always on sale and there are store brand sodas available. As for using whole milk – totally rididulous when its been noted that even 2% milk provides too much fat per serving.

  2. NotCinderell says

    I hate cost/calorie assessments in general, because they don’t make sense and always amount to a tautological argument. “Calorie-dense foods are more calorically dense than non calorie-dense foods.” No kidding?

    No shopper is thinking in terms of cost/calorie when they shop. They think in terms of cost/serving.

  3. Viki says

    I know I’ll get scolded for this but all the reading I’ve been doing suggests that we have been sold a bunch of bunk about Low Fat. Hear me out. Whole milk will fill the kids up, the fat will not only make them feel full for longer than the soda pop, but it will also improve their brain function. Our bodies need some fats to function.
    Studies in Europe show that women who drink whole milk actually lose weight. They don’t guzzle it by the gallon, but a glass a day is okay.
    I went to grade school in the 60’s and I don’t remember being served anything but whole milk in school. Of course the lunches were made In the kitchen at the school too, not shipped in and reheated. Not too many kids in my school were overweight that I remember, but it has been awhile.
    I agree the HF’s math is Fuzzy.
    Did you read the second article about that family? The middle child has a good head on her shoulders.

    • bettina elias siegel says

      Vicki – no scolding here. I’m all for whole milk over soda, if that’s the choice. And, yes, fat is important for satiety and we certainly need a certain amount in our diet. But I do think if someone’s goal is to lose weight, most experts would recommend lower fat milk over whole. So, I was just pointing out that in the context of a report about combatting obesity, it was pretty notable (and suspicious) that the Heritage Foundation used whole milk in its calculations. Does that make sense? – Bettina

  4. Karen says

    That is some wacky math the HF is doing. Amazing that they can say that with a straight face.

    But all I was thinking when I heard that boy on the NPR story reach for the orange soda was “what about a nice glass of cold water from the tap?”

    When we come back from playing outside and we’re hot, we’re drinking water. Cold water.

  5. bettina elias siegel says

    Karen: I swear I was going to ask you (my rocket scientist friend) to check my math! Glad to hear it passed muster. :-)

  6. Mendy says

    Thanks, Bettina – this is very interesting. I get very angry when I read what groups like the HF are doing. We live in a world that thrives on unreliable statistics and lacks common sense. If schools could (or would) educate kids about nutrition and budgeting, then kids could take that info home to their parents. From experience, I know these topics interest kids and they are quite easily woven into math, science and language arts lessons.
    Sadly, many people will read this report from the HF and be convinced that everyone who is poor wants to be fat!

    • bettina elias siegel says

      Mendy: You’re absolutely right. And I noted that a math teacher re-tweeted my post! Maybe it’s going to be an exercise for some group of kids — I’m sure they’ll arrive at the right answer faster than I did. :-) BTW, I swear I’m sending interview questions your way. I know I’ve been saying that for some time, but I really will do it. If not in the next few weeks, then definitely once school is back in session.

  7. Rachel says

    It must really depend on where you live and shop. Here in Texas (DFW) I shop at Aldis (easily accessible from public transit) and a GALLON of milk cost 99 cents. A two liter of soda costs 69 cents. I can guarantee no one around here is buying the soda because its cheaper than the milk.
    Skim comes in at 1280 calories for $1
    Whole milk is 2400 calories for $1
    Soda is 1159 calories for $1
    I think the real problem with the whole argument is that no dietitian anywhere would recommend you obtain your calories in liquid form. Eat an orange instead of drinking orange juice–sugar devoid of fiber and substance is just empty calories. If you want to make an argument for a cheap/high calorie sugary drink, use Kool-aid, your math will look better, 25 cents for two liters or 3096 calories for $1 .
    I shop for our family of 5 on $400 a month, no food stamps, free lunch, or other welfare and we eat very healthy. Lots of vegetables, fruits, whole grains, and meats. It makes me angry as someone who has very limited resources but feeds my family well on that budget to read people making excuses for their poor choices just because they are poor. Rich people make dumb decisions for their families too, but nobody is criticizing them because they pay their own way. If you want me to pay for your food, don’t ask me to pay for your diabetes care too when you spend the money on soda.
    And please, I have all the compassion in the world for people who truly need it, I regularly contribute to my local food pantry because I hate to think of anyone anywhere going hungry. I just don’t buy the whole ‘junk food is cheaper’ nonsense. Have a glass of water and buy a can of pork n’ beans–980 calories for $1 that will fill you up and keep you full. And your teeth won’t rot and your toes won’t fall off. Everybody wins.

    • bettina elias siegel says

      Rachel – that’s interesting information re: price and I appreciate you sharing it here. So maybe my calculations don’t hold up everywhere. I guess my only objection to your comment is that people on the low end of the socioeconomic ladder might lack the education to know they’re making a dumb choice. I’m sure that’s not true in all cases of people using food stamps to buy soda, but it’s likely true in many cases. What do you think?

  8. factchecker says

    The heritage foundation wants to score political points even at the expense of credibility depending on what mood or propaganda they want, for instance if a “liberal” organization has a valid point of something in which certain conservative libertarians agree on, a group of conservative “heritage foundation” folks may still go against the opinion, an example being trying juveniles in adult courts, the heritage foundation favors a proposal only because liberals are against it, ignoring that conservative folks want to limit prosecutors influence for folks still under parental control, and ignoring that heritage has supported broad statutory rape laws under the same principal, the idea that juveniles are immature to fully comprehend their decisions,

    Soda is nutritious food, just like juice, white pita, etc, the problem is diet and exercise, poor decisions and choice, soda by itself is sugar and water, so to fill a person up you can go cheaper, since the markup reflects carbonation and flavoring, however meats and oil are cheaper due to longer shelf life than vegetables.

    A blue collar construction worker who is white and on food stamps and probably lives in west Virginia may very well need the calories from junk food, soda, vitamin water, and gatorade, you see all the nba players drinking gatorade, but bloomberg wants to ban junk food? By contrast a white collar worker at the computer desk needs fewer calories, however conservatives and liberals alike want to model it for a white collar worker, a meal/diet plan similar to wic, which is for infants, then of course take a teenage athlete who’s mother is on food stamps and says sorry child, no high calorie food, defining junk food is another story, for instance is granola junk food, or apple juice or dole’s mango or peach junks in syrup, or ice cream vs. greek fruit/honey yogury or chocolate yogurt, after all juice is basically the sugar/water no roughage is really present.

    • Bettina Elias Siegel says

      Factchecker – Yes, I agree that the HF wants to schore political points at the expense of credibility. I wouldn’t agree with your assessment that soda is “nutritious food.” Just because a food contains calories, those calories can be entirely devoid of nutrients, as with the case of soda. And while I agree that defining “junk food” would be a huge challenge, I don’t believe Bloomberg has ever made such a proposal. I’m only aware of his effort to block the purchase of soda with food stamps, an effort which I supported but which ultimately failed. Thanks for commenting here on TLT.


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