The USDA’s “My Plate” Makes No Sense

If you’ve ever watched Sesame Street, you may remem­ber the song about cat­e­gories: “One of these things is not like the oth­ers. One of these things just doesn’t belong.” That song ran through my head when I looked at the USDA’s My Plate food group sys­tem, which fea­tures veg­eta­bles, fruits, grains, dairy, and pro­tein. One of the foods groups isn’t like the oth­ers and just doesn’t belong. Can you guess which one?

Con­tin­ue read­ing “The USDA’s “My Plate” Makes No Sense”

Potatoes Provide Plenty of Protein!


Most diet-con­scious peo­ple today think of pota­toes as “a starch.” They think that if you are hav­ing pota­toes for din­ner, you still have to add “a pro­tein” to your meal. Yet pota­toes are an excel­lent source of pro­tein. Sci­en­tists have known that since the 1920s because of an inter­est­ing exper­i­ment that was done in Poland in 1925 and pub­lished in 1928 in Bio­chem­i­cal Jour­nal.  Thanks to the Inter­net, you can read the orig­i­nal arti­cle for your­self.

The researchers knew that pop­u­la­tions that sub­sist­ed on a diet based heav­i­ly on pota­toes seemed to be healthy and remark­ably free of scurvy, beriberi, and pellagra—diseases that were known to result from vit­a­min defi­cien­cy. Some ear­li­er work had sug­gest­ed that pota­toes can pro­vide enough pro­tein for human nutri­tion, and this study was intend­ed to con­firm those results.

For 167 days, the researchers fed a healthy young man and a healthy young woman a diet whose only sig­nif­i­cant source of pro­tein was pota­toes. Besides pota­toes, the sub­jects ate fat and salt and a few apples and pears. They could also have the occa­sion­al cup of black cof­fee or tea with sug­ar.

The sub­jects thrived on this lim­it­ed diet. Their health remained good and their weight remained sta­ble, except that the man start­ed los­ing weight toward the end of the study as he got more seri­ous with his ath­let­ic train­ing. Nitro­gen bal­ance stud­ies con­firmed that they weren’t hav­ing any trou­ble with pro­tein defi­cien­cy. Most sur­pris­ing­ly, they didn’t get bored with their monot­o­nous diet! To show that these results weren’t some sort of fluke, look at what hap­pened when some­one from the Wash­ing­ton State Pota­to Com­mis­sion ate noth­ing but pota­toes for 60 days.

At the end of the arti­cle, the authors thanked Dr. Casimir Funk, who direct­ed the exper­i­ment. Funk was a super­star in the his­to­ry of nutri­tion. In 1912, he pub­lished a land­mark arti­cle describ­ing how he had iso­lat­ed thi­amine, the chem­i­cal that is respon­si­ble for pre­vent­ing and cur­ing the defi­cien­cy dis­ease called beriberi. That same year, he wrote anoth­er land­mark arti­cle, which sug­gest­ed that sev­er­al epi­dem­ic dis­eases were actu­al­ly the result of a defi­cien­cy of some vital chem­i­cal that was need­ed in only tiny amounts. He guessed that, like thi­amine, the oth­er chem­i­cals would be amines, so he coined the term “vit­a­mines.” After it turned out that some of these vital chem­i­cals aren’t amines, the “e” was dropped, and they became vit­a­mins.

As this study showed, pota­toes con­tain plen­ty of pro­tein. So the next time that you think you need to add “a pro­tein” to your meal, eat a pota­to!

No, It’s a Low-Fat, High-Fiber Diet That Keeps Gorillas Lean!

A recent arti­cle in the New York Times argued that goril­las stay slim because they eat a high-pro­tein diet. While I’m glad to see some­one else point out that a plant-based diet pro­vides ade­quate amounts of pro­tein, I’m annoyed to see sci­en­tists and jour­nal­ists mis­un­der­stand and mis­rep­re­sent the real sig­nif­i­cance of this fact. It’s as if they haven’t read the basic lit­er­a­ture on nutri­tion and can’t under­stand arith­metic.

Yes, the gorilla’s nat­ur­al diet is high in pro­tein, as a per­cent­age of calo­ries. How­ev­er, the goril­las’ nat­ur­al food tends to be low in calo­ries, because the calo­ries are dilut­ed by water and fiber. Goril­las have to eat an enor­mous amount of food every day to get enough calo­ries. When human vol­un­teers tried to eat a goril­la-style diet for a short peri­od of time to see how it would affect their cho­les­terol lev­els, they had to spend more than 8 hours a day eat­ing, just to get enough calo­ries to keep from los­ing weight dur­ing the tri­al. Goril­las stay slim because of the high fiber con­tent and low fat con­tent of their food, not because of the bal­ance of pro­tein to car­bo­hy­drate in their food!

The biggest dietary chal­lenge for a goril­la, as for any leaf-eater, is to get enough calo­ries. When they eat a rel­a­tive­ly high-pro­tein diet, they just end up con­vert­ing the excess pro­tein to sug­ar and burn­ing it for ener­gy. Unfor­tu­nate­ly, pro­tein is “dirty sug­ar.” Burn­ing pro­tein for ener­gy pro­duces waste prod­ucts such as urea and sul­fu­ric acid.

Peo­ple can stay very slim on a high-car­bo­hy­drate diet, if it is also high in fiber and low in fat. For exam­ple, when Chris Voigt of the Wash­ing­ton State Pota­to Com­mis­sion decid­ed to go on a pota­to-only diet as a pub­lic­i­ty stunt, he fig­ured that he had to eat 20 pota­toes a day. In prac­tice, he found it real­ly hard to eat his entire pota­to ration, because pota­toes are so fill­ing. As a result, he lost a lot of weight. Even when he made an effort to eat his entire pota­to ration every day, he con­tin­ued to lose weight. That’s because a starchy diet improves insulin sen­si­tiv­i­ty and thus revs up your metab­o­lism. Peo­ple who eat starchy diets burn more calo­ries than peo­ple on fat­ty diets. Voigt lost 21 pounds dur­ing his 60-day pota­to diet. His cho­les­terol lev­els, triglyc­eride lev­els, and even his blood sug­ar lev­els decreased!

Accord­ing to the New York Times, Dr. Rauben­heimer claimed that mod­ern soci­eties “are dilut­ing the con­cen­tra­tion of pro­tein in the mod­ern diet. But we eat to get the same amount of pro­teins we need­ed before, and in so doing, we’re overeat­ing.” What non­sense!

Nutri­tion sci­en­tists have known for more than 100 years that human pro­tein needs are mod­est and are eas­i­ly met by any rea­son­able plant-based diet. Also, the soci­eties with the biggest prob­lem with obe­si­ty are also the ones with the high­est pro­tein intake! Mod­ern soci­eties are con­sum­ing too much fat and too lit­tle fiber. Ani­mal foods are a big offend­er, because they con­tain fat but no fiber and usu­al­ly no digestible car­bo­hy­drate. Refined foods are also a big offend­er, because they rep­re­sent the con­cen­trat­ed calo­ries from plants–with the fiber and oth­er whole­some things stripped out.

The take-home les­son from the goril­la sto­ry shouldn’t have been that peo­ple need to eat more pro­tein. It’s that peo­ple need to eat plants. If peo­ple don’t want to spend 8 hours a day eat­ing leafy veg­eta­bles, they can eat some nice, fill­ing pota­toes or oth­er starchy sta­ples along with plen­ty of veg­eta­bles and fruit.

Plants Provide Everything But Vitamin D and Vitamin B12

Vit­a­min D Comes From Sun­shine, Vit­a­min B12 From Bac­te­ria

How can a diet con­sist­ing main­ly of leaves give goril­las enough pro­tein to grow big and strong? It’s because leaves con­tain pro­tein. Leaves are low in calo­ries, but a lot of their calo­ries come from pro­tein. In fact, most ordi­nary plant foods con­tain more than enough pro­tein to meet human nutri­tion­al needs. Nutri­tion sci­en­tists have known for near­ly a hun­dred years that as long as you are eat­ing any rea­son­able plant-based diet, if you take care of the calo­ries, the pro­tein takes care of itself.

It’s hard even to design a plant-based diet that would be defi­cient in pro­tein while pro­vid­ing enough calo­ries. You’d have to include noth­ing but some low-pro­tein fruit, such as apples. Or you could cheat and use sug­ars and fats that have been extract­ed from plants, leav­ing the pro­tein and oth­er nutri­ents behind.

Not only do plants pro­vide enough pro­tein for human nutri­tion, the pro­teins they con­tain are nutri­tion­al­ly “com­plete,” as far as human pro­tein needs go. That means that they con­tain enough of all of the dif­fer­ent amino acid “build­ing blocks” that human bod­ies need.

The only “incom­plete” pro­tein you are like­ly to find on your din­ner plate is gelatin, which comes from ani­mal bones. Gelatin is incom­plete because tryp­to­phan is destroyed in the man­u­fac­tur­ing process. You’d get very sick if you tried to use gelatin as your sole source of pro­tein.

Plant foods also con­tain the min­er­als that are essen­tial for human nutri­tion. Plants absorb these min­er­als, such as cal­ci­um and iron, from the soil. After all, where did the cows get the cal­ci­um that goes into their milk? Where did they get the iron that goes into their flesh?

Plants also pro­vide near­ly all of the vit­a­mins that are essen­tial in human nutri­tion. The excep­tions are vit­a­min B12, which is made by bac­te­ria, and vit­a­min D, which your body can make for itself if you go out­side in the sun­shine. Peo­ple who eat a pure­ly plant-based diet are gen­er­al­ly advised to take a vit­a­min B12 sup­ple­ment. Whether you need a vit­a­min D sup­ple­ment depends on how dark your skin is and where you live. Your doc­tor can do a sim­ple blood test to see whether you have enough of both of these vit­a­mins.