Getting Antioxidants on a Budget

Recently, I posted about the problem that cheaper foods tend to include a lot of junk foods. For instance, you can easily get all your daily calories by buying the cheapest options at McDonalds or by buying M&Ms in bulk. That post left open the question: what should I eat if I want to get good nutrition and stay on a budget?

I took a simplified look at this problem. In addition to calories, I looked at the ORAC level of foods, which is a measure of their antioxidant power. To do this, I found an excellent ORAC table from the USDA. ORAC levels are often quoted per 100 gram sample (about 1/4th of a pound, or 4 oz). While this is a fair basis for comparision, it is fairly irrelevant to an eater. As an eater, I care much more about the ORAC units per calorie or ORAC units per dollar. The limits of my calorie budget (to avoid obesity) or my financial budget (to avoid bankruptcy) are much more restrictive than my limits due to stomach size. Doing evaluations on price is more difficult because unlike ORAC density or calorie density, price is not a property of the food, but of a local and fluctuating market. So, your results may be slightly different, but I collected these prices from the lowest available in my area (Gainesville, FL, USA) during late 2008 and early 2009. The results are as follows.

If I only want to maximize ORAC per calorie, which is to say: “price be damned, I only care about not getting too fat”, these are the foods that will help me do that:

Food Orac/100g Cost/100g Cal/100g Orac/cal Orac/dol
Tea, green, brewed 1253 0.02 1 1253.0 71697.55
Spices, Cinnamon, ground 267536 0.66 247 1083.1 406225.23
Spices, cloves, ground 314446 17.21 323 973.5 18272.73
Spices, oregano, dried 200129 3.53 306 654.0 56636.51
Spices, turmeric 159277 5.94 354 449.9 26830.59
cocoa dry powder, unsweeted 80933 3.45 229 353.4 23470.57
Spices, basil, dried 67553 0.66 251 269.1 102572.11
Coriander (cilantro) raw 5141 1.4 23 223.5 3683.3
Ginger root 14840 0.81 80 185.5 18258.43
Plums (raw) 6259 0.42 46 136.1 15034.85
Blueberries, raw 6552 0.69 57 114.9 9463.23
Strawberries 3577 0.37 32 111.8 9759.36
Spices, pepper, black 27618 2.56 255 108.3 10798.42
Spices, Ginger, ground 28811 5.3 347 83.0 5435.68
Apples Granny Smith (with skin) 3898 0.42 52 75.0 9363.45
Spinach, raw 1515 0.85 23 65.9 1791.17
Goji Berries 25300 2.35 400 63.3 10775.05
Red table wine (cab) 5034 0.53 83 60.7 9438.75
Apples (with skin) 3082 0.37 52 59.3 10846.73
Spinach, frozen 1687 0.28 29 58.2 6105.13
Peppers, sweet, green, raw 923 0.28 20 46.2 3248.39
Applesauce canned, unsweeted 1965 0.19 43 45.7 10492.36
Juice, Concord Grape 2377 0.25 57 41.7 9582.49
Beets, raw 1767 0.66 43 41.1 2683
Broccoli, raw 1362 0.39 34 40.1 3534.96
Dark Chocolate 20823 3.5 520 40.0 5949.43
Peppers, sweet, orange, raw 984 1.1 25 39.4 895.26
Onions, red, raw 1521 0.28 40 38.0 5352.98
Oranges, raw, navals 1819 0.44 49 37.1 4149.88
Grapefruit, pink red 1548 0.15 42 36.9 10068.65
Garlic 5346 0.5 149 35.9 10598.62

Notice, that spices are so high in ORACs, they are an easy way to increase the ORACs in your diet. There are some of the usual suspects up there as well: green tea, berries, apples, spinach, red wine. Tea has almost no calories, so it naturally will be high on this list.

But let’s look at how to get a sufficient amount of ORACs within both a calorie and financial budget. To do that, we need to identify the budget. Exactly how many ORACs a person needs is probably not a completely well defined question because of individual differences and the limitations of ORACs as some kind of unified measure of nutrition (which it is not, and I am not claiming that it is). That having been said, I’ve seen the number 5000 ORAC/day as a target (which is approximately what you’d get if you get 5 servings of most fruits or vegetables a day). For the calorie budget, I’ll assume 2000 calories per day (get a better estimate for yourself with the Nutritiondata.com daily needs tool). For the financial budget, I found a 2003-2004 USDA study on food spending that found that the poorest 20% spent on average 1737 per year in 2004, so that gives us 4.76 to spend per day. Since many high ORAC foods are not consumed in large quantities (such as spices), but some other medium ORAC foods are (such as beans or shreaded wheat), I limited the foods to more than 272 cal/dol, which is $7.35/day. I did this to get a list of 20 foods. Then I sorted them according to highest ORAC/dollar. The following list is the cheapest way to get ORACs and still get enough calories each day to not spend too much on food:

Food Orac/100g Cost/100g Cal/100g Orac/cal Orac/dol cal/dol
Spices, Cinnamon, ground 267536 0.66 247 1083.1 406225.23 375.04
Spices, basil, dried 67553 0.66 251 269.1 102572.11 381.12
Beans, kidney, raw 8459 0.22 333 25.4 38403.86 1511.82
Beans, black, raw 8040 0.22 341 23.6 36501.6 1548.14
Lentils, raw 7282 0.22 353 20.6 33060.28 1602.62
Plums (dried) 6552 0.44 240 27.3 14902.38 545.87
Garlic 5346 0.5 149 35.9 10598.62 295.4
Grapefruit, pink red 1548 0.15 42 36.9 10068.65 273.18
Nuts, pecans 17940 1.98 691 26.0 9059.8 348.96
Nuts, walnut 13541 1.65 654 20.7 8207.76 396.42
Raisins, seedless 3037 0.49 299 10.2 6156.67 606.14
Bananas 879 0.15 89 9.9 5783.57 585.59
Potatoes, red, flesh and skin, raw 1098 0.22 70 15.7 4994.91 318.44
Peanuts, raw 3166 0.66 567 5.6 4791.21 858.06
Nuts, almonds 4454 1.54 575 7.7 2892.87 373.46
Cereal, shreaded wheat plain 1303 0.66 340 3.8 1986.53 518.36
Popcorn, airpopped 1743 0.99 387 4.5 1757.1 390.13
Watermelon, raw 142 0.11 30 4.7 1293.67 273.31
Nuts, cashew 1948 1.87 553 3.5 1041.69 295.71
Olive oil, extra virgin 1150 1.27 884 1.3 907.34 697.47

It’s interesting that when we sort by ORAC/dollar and put a price threshold, very different foods show up. We can see how great beans are with this list: when you buy dried beans in bulk you get an extremely healthy food which is also extremely economical: more than 1500 calories per dollar! Of course, these prices assume you are getting the very best deals: so one needs to shop at club stores and buy food from the bulk bins. Dried Plums, or Prunes, also show up as big winners: about twice the ORACs/dollar of raisins with about the same calories/dollar. Notice also, that stawberries and blueberries are great (high ORAC/calorie as we saw in the first chart), but they are too expensive to form a significant portion of your calories. When it comes to nuts, pecans and walnuts are excellent choices: they give you lots of ORACs and lots of calories.

One last point I want to make is that paying attention to the seasonal sales in fruits and vegetables makes a lot of sense. The prices may change by more than a factor of three as items go in and out of season, so make sure to try to choose seasonal vegetables and fruits. Also, compare the calories/dollar of canned, frozen and dried vs. fresh fruits and vegetables. Often fresh costs more and in many recipes you won’t notice any difference.

You can find the above data on a google spreadsheet containing the ORAC data.

Update 3/10/2009: Here’s a related NY Times article: “Eating Well on a Downsized Food Budget” published 3/2/2009.

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The Cost of Eating Well

About a month ago, I was shocked by an interview I heard while driving home. The radio program Florida on the Line had Holly Benson, secretary of the Agency for Health Care Administration, as a guest. The interviewer asked Holly if the economic downturn would have an impact on health. Holly responded, “just because you’re poor doesn’t mean you’re unhealthy; it just means you have a lot more time to go running.”

I was disappointed that this question was not seriously addressed (and by the callousness of the response). In fact, being poor does impact your health. Those with the lowest income have the highest rate of obesity. The fact is, the cheapest foods are not the healthiest (related article at CNN). Sugar is cheap:

All that corner-store processed food is relatively inexpensive – artificially so. Researchers say that many junk foods contain high-fructose corn syrup, made from government-subsidized corn crops. Federal help keeps the cost of syrup-containing foods such as sodas, fries and even burgers down. Drewnowski said that healthful, unsubsidized foods like spinach cost five times more per calorie to produce, thus driving up the price (from Philadelphia Inquirer).

As an engineer, I like numbers. So, what are some example calories-per-dollar ratios? Since I try to eat healthy and keep a spreadsheet of all the foods I eat at home, computing calories-per-dollar for all my recipes is easy. Here are some examples from my spreadsheet:

Food calories/dollar
Peanut Butter 978
Peanuts 889
Oats 741
Whole Wheat Bread 420
Almonds 387
Kashi Bars 316
Nonfat Milk 268
Canned Beans 262
Pistachios 258
Grapes 185
Frozen Strawberries 159
Fat-free Yogurt 122
Tempeh 115
Canned Tuna 107
Oranges 107
Cooked Turkey 89
Carrots 62
Blueberries 54
Tomato 48
Spinach 28

Notice anything? All the produce is significantly more expensive than the fats and grains. McDonald’s sells cheeseburgers for 59 cents on some days. Since those cheeseburgers are about 300 calories, that gives you 504 calories/dollar. Of all the things in the above list, McDonald’s cheeseburgers are the fourth cheapest! If you eat 2000 calories/day, you could survive on 4 dollars a day on McDonald’s cheeseburgers. You’d get more than 100% of your fat and cholesterol, and only 8% of your Vitamin C, but you’d get 100% of your calories.

Perhaps you like sweets instead of cheeseburgers. You can buy 56 oz of Peanut M & M’s for 15.99 which gives you 8065 calories, or 504 calories per dollar, the same as the cheeseburger!

Being healthy and avoiding disease requires more than cheap calories, it requires getting sufficient vitamins and other nutrients. Unfortunately, in the United States, between 5-17% of the population is Vitamin C deficient.

If you were at risk of starving would you purchase spinach at 28 calories per dollar or peanut butter at 978 calories per dollar? This is a problem I don’t hear addressed very often in the obesity discussion. We need to look more at the cost-per-calorie of healthy choices. This is an area where the government could help. We should tax unhealthy choices, and subsidize healthy choices. Since humans’ tastes are set for a food landscape that does not exist today, namely scarcity of sweets and fats, we need to leverage other mechanisms such as economics to help make better choices.

The Freakonomics of Human Fuel Economy

With gas prices high, I’ve heard a lot of articles assert that biking gives infinite miles per gallon. While it is true that humans don’t use gas, it’s not true that they don’t use energy.

When one walks, runs or bikes, one burns energy that would otherwise go unburned. For walking (4 mph), running (10 mph), and biking (11.9 mph) a 155 lb person burns 281, 1126, and 422 calories per hour respectively (according to this site). We can compute the calories per dollar of cheap food sources, such as grains (741 calories/dollar) or peanuts (867 calories/dollar). Let’s assume one can average 800 calories per dollar (which assumes spending about $2.50 per day on food on a 2000 calorie diet), which is a pretty generous assumption.

Let’s compute the miles/dollar assuming 800 calories/dollar: walking gives 11.4 miles/dollar, running gives 7.1 miles/dollar, and biking gives 22.6 miles/dollar. Assuming a gallon of gas is worth 4 dollars, we can express miles per dollar as miles per gallon. This means walking, running and biking converts to 45 mpg, 28 mpg and 90 mpg respectively. Very few Americans spend as little as $2.50/day on food. In fact, $10/day is probably more realistic. Assuming instead 200 calories/dollar (10 dollars/day), we get something like 11 mpg, 7 mpg, 22 mpg for walk, run, and bike. The only way I can beat the economy of my Prius is to bike and fuel that bike ride with ultra-cheap food sources.

Don’t get me wrong, exercise is great. I run, walk and bike a lot. Additionally, most Americans are eating more calories per day than they need, and could possibly bike for transportation without increasing their calorie intake. But, it is not the case that humans are much more efficient than cars.