No edible plant has a more foul reputation than the white potato. Scorned, spat on, uttered in the same breath as pizza and candy, nearly banned from school cafeterias,1 the hapless white potato is a perennial fixture in Pop Nutrition’s dog house.
Somewhere along the way, we forgot white potatoes are whole-food vegetables.
Hat in hand, the humble white potato offers us a significant amount of fiber, Vitamin C, Vitamin B-6, niacin, thiamin, folate, phosphorus, magnesium, copper, iron, manganese, and potassium.4 (Know how they say bananas are high in potassium? Please. Per gram, baked potatoes have 54% more.5,6)
Quite the plethora.
There are more praises to sing. But first, how did things get so bad for the spud?
Two big reasons.
Look at this tangle of thorns.
Snafu 1: The Glycemic Index
People like to think of incredibly complex things in incredibly simple ways.
The chemical tango between our bodies and food is mind-boggling, our understanding still fairly infantile. Yet we fancy we can sum it up with barnyard tools like the glycemic index and/or glycemic load, which attempt to describe a food’s effect on human blood sugar—with a single number.
They say high-glycemic foods are bad, and white potatoes are very high-glycemic—and thus, the devil.
Where do I begin?
First, a food’s “glycemic index” is the crudest of averages. There’s huge variability in a food’s index between studies,7 and even huger variability in different people’s blood-sugar responses to identical meals.8
One person’s glycemic roller coaster is another’s lazy river.
But even if we responded the same, glycemic values would not be very meaningful. This is because high-glycemic foods usually aren’t eaten alone. A high-GI carb is typically eaten with fat and/or protein, which significantly blunt the sugar spike.9
Regardless, we have evidence of people eating almost nothing but high-glycemic carbs their whole lives and being healthy and thin, with no obesity and no diabetes. Like the Murapin, who ate almost nothing but sweet potatoes (which have a high glycemic index and glycemic load10) and had no heart disease, diabetes, or obesity.
These people prove high-GI carbs are not inherently bad.
Is there any merit to the glycemic index? Sort of.
Most (not all) of the highest-glycemic foods are junk foods: bagels, pizza, fruit-roll-ups, etc.
So it isn’t surprising that—in a vacuum—people who eat high-glycemic diets get more diabetes13 and that telling people to avoid high-GI foods leads to slightly better outcomes than some other approaches.14 (Because they’re eating less junk.)
But in practice, glycemic numbers are awful decision-making tools.
Want sweet potatoes? Sorry, bro! They have a high glycemic index and an even higher glycemic load. Prefer chicken nuggets, Wonder Bread, and waffles—all of which have less than half the glycemic load of sweet potatoes.15
And don’t even think about white potatoes, whose GI is even higher.
Instead, choose M&M’s, ice cream, Snickers bars, and soda—all of which have a much lower glycemic index and a much lower glycemic load than the white potato.16 (The whole-food, nutrient-packed, vegetable white potato.)
See the problem?
A skeptic might say, “just choose healthy foods with low-to-moderate GIs.”
To which I’d say, “you just admitted healthy foods can have high GIs.”
With a quick and dirty look at the science, the glycemic theory unravels.
A 2016 meta-analysis of 19 randomized controlled trials found that low-GI diets did not cause significantly more weight loss than high-GI diets.17 Some trials even found high-GI diets better for weight loss.18
A 2013 review of randomized trials where dieters were actually provided with the foods they ate (as opposed to just given guidelines, which are much less reliable) did not find any significant benefit for low-GI vs. high-GI diets for various important health markers. Two of the trials even found better blood-sugar results from high-GI diets19 (precisely the opposite of what you’d expect).
But forget the word glycemic.
We’re talking potatoes. Let’s get it from the horse’s mouth. A 2016 review of 13 potato studies found that:
the identified studies do not provide convincing evidence to suggest an association between intake of potatoes and risks of obesity, T2D [diabetes], or CVD [heart disease].”20
It seems the high GI of potatoes is about as dangerous as Mr. Rogers.
But they did find that:
French fries may be associated with increased risks of obesity and T2D.
Which brings us to…
Snafu 2: Bad Company
Much of spuds’ wretched repute comes down to guilt by association.
Through no fault of their own, potatoes go great with fat, have a perfect texture for frying, and are rarely eaten naked.
More than any other plant, white potatoes are smothered with butter and bacon, fried in vegetable oil, and coated with salt. This is highly fattening.
Nothing illustrates the Bambi innocence of white potatoes and the Cruella guilt of added fat better than one of the most illuminating studies in the history of nutrition: Holt et al.’s 1995 masterpiece, “A Satiety Index of Common Foods.”21
satiety: the feeling of fullness
Most people stop eating when they feel full, more or less.
But, per calorie, different foods are more filling (satiating) than others. So if you eat a lot of un-filling (un-satiating) foods, you’ll need more calories to feel full.
And if you’re an average person, you’ll slowly get fat. (Womp womp wompp.)
This glorious study found that junk foods—foods with white flour, added sugar, and/or added fat—are almost universally less filling than whole foods.
(Side note: the main cause of the obesity epidemic is people eating these un-filling junk foods on a massive scale.)
The goal of the study was to measure the satiating power of 38 common foods. People ate 239-calorie portions of each food, reported their level of fullness, and were offered a buffet two hours later and told to eat freely.
Sure enough, the more filling someone rated a food, the less buffet food they ate after.
Each food got a satiety score.
What food was the most filling?
Amid stiff competition from fruit, ling fish, porridge, lentils, eggs, brown rice, beans, and steak (all whole foods), the clear winner was the white potato, which summarily crushed every other food.
|most filling||score||least filling||score|
|whole-wheat pasta||188||strawberry yogurt||88|
|beef steak||176||potato chips||91|
|(all whole foods)||(all processed)|
The white potato beat 2nd-place by 44%. It was a bloodbath.
Far from being fattening, this suggests white potatoes are highly slimming.
But in starkest contrast, potato chips were among the least satiating foods, scoring even worse than jelly beans and ice cream (not pictured).
How could this be?
As the study shows, the problem with potato chips is crystal clearly not potatoes.
A better name for potato chips would be “vegetable-oil chips.”
In a bag of potato chips, more calories come from vegetable oil than potatoes.22 (Have I ever told you that vegetable oil is over 20% more calorie-dense than butter?23,24 That many types of vegetable oil are associated with heart disease?25 That vegetable oil is utterly ubiquitous?)
Shower potato slices in vegetable oil and sprinkle salt on top (the only three ingredients in your standard chip) and you take a food with world-class satiety and demote it to a level below ice cream.
If you took, say, kale, and bathed it in vegetable oil and doused it with salt, those kale chips would also be fattening (not because of kale).
Mashed potatoes (add butter, mash, soak in white-flour-laden gravy), potato chips, and French fries are not “potatoes.”
Enough foreplay. What would happen to you if you ate tons of potatoes every day for a long period of time?
We have the data.
In a 1927 study, a 142-pound man and a 140-pound woman were put on a diet of (mainly) potatoes—and allowed to eat freely—for 167 days.28
(There used to be weird and useful studies like this.)
The odd couple ended the study at 135 and 136 pounds, respectively—with no bad health effects. The scientists remarked that “digestion was excellent throughout the experiment and both subjects felt very well.” Remarkably, neither of them lost any muscle, even though potatoes were their sole source of protein, and even though the guy was very active.
What about regular people eating potatoes on the regular? In a study of 77 Peruvian men whose regular diet was ~74% white potatoes, average body-fat percentage was in the “fitness” range, according to ACE’s body-fat chart.29,30,31 (They were eating 3,170 calories a day; food-deprived they were not.)
In 2010, the zealous director of the Washington State Potato Association went on a 60-day potato diet during which he ate nothing but white potatoes (20 a day) to protest the US government’s potato restrictions in school lunches. He lost 21 pounds and saw massive drops in his cholesterol, triglycerides, and (gasp) blood sugar.32,33
And this Australian blogger claims to have eaten nothing but potatoes for a year and lost 117 pounds.
The Best Food on Earth
“No food [but the potato] can afford a more decisive proof of its nourishing quality, or of its being peculiarly suitable to the health of the human constitution.”34
—Adam Smith, The Wealth of Nations
If we define “food” as an edible thing that can sustain human life, many of the so-called healthiest foods are instantly disqualified.
If all you had to eat were broccoli, kale, asparagus, Swiss chard, and Brussels sprouts, you’d quickly wither away and eventually die—either of starvation or obscure intestinal problems caused by eating grotesque amounts of greens in a desperate attempt to get enough calories. (You’re not a gorilla. You can’t digest cellulose.)
Like many other veggies, these grandiose greens are more like natural vitamins than actual foods. They’ve never sustained a human population. People need lots of calories to live.
And calories have to come from somewhere.
The white potato is almost single-handedly capable of sustaining human life indefinitely—which is just what it’s done. White potatoes have backboned entire civilizations, from the Incas35,36 to the Irish37 to the Russians.38
Given the abundance and geographic range of potatoes and similar plants, some eminent anthropologists believe the invention of fire wasn’t mainly driven by the desire to cook meat, but to cook potato-like tubers.41
Either way, we’ve been eating foods like potatoes since time immemorial.
That’s always a good sign.
What else? Did I mention white potatoes are as cheap as the dirt they grow in? Where I live, a 5-pound bag is two bucks.
You can’t put a price on…price.
Well, there you have it. For many reasons, the wh…wait.
I almost forgot. There’s one more thing.
As The Economist states, the white potato “provides more calories, more quickly, using less land and in a wider range of climates than any other plant.”44
In a time of great environmental concerns, this makes white potatoes the greenest food on Earth.
The most environment-friendly food choice you could possibly make is to base your diet on white potatoes.
Let that settle.
When you combine this extreme eco-friendliness with extreme affordability, great taste, phenomenal nutritional value, and a time-tested and crucial role in human civilization, you get…
The best food on earth.
Your calories have to come from somewhere.
Shouldn’t they come from a vegetable?
11. Lindeberg, Staffan. Food and Western Disease: Health and Nutrition from an Evolutionary Perspective. Hoboken: Wiley-Blackwell, 2010. Kindle File, Chapter 4.1, Location 1695 of 11554.