Good calories, bad potatoes?

By Razib Khan | June 23, 2011 2:02 am

Changes in Diet and Lifestyle and Long-Term Weight Gain in Women and Men:

Within each 4-year period, participants gained an average of 3.35 lb (5th to 95th percentile, −4.1 to 12.4). On the basis of increased daily servings of individual dietary components, 4-year weight change was most strongly associated with the intake of potato chips (1.69 lb), potatoes (1.28 lb), sugar-sweetened beverages (1.00 lb), unprocessed red meats (0.95 lb), and processed meats (0.93 lb) and was inversely associated with the intake of vegetables (−0.22 lb), whole grains (−0.37 lb), fruits (−0.49 lb), nuts (−0.57 lb), and yogurt (−0.82 lb) (P≤0.005 for each comparison). Aggregate dietary changes were associated with substantial differences in weight change (3.93 lb across quintiles of dietary change). Other lifestyle factors were also independently associated with weight change (P<0.001), including physical activity (−1.76 lb across quintiles); alcohol use (0.41 lb per drink per day), smoking (new quitters, 5.17 lb; former smokers, 0.14 lb), sleep (more weight gain with <6 or >8 hours of sleep), and television watching (0.31 lb per hour per day).

I took the results when they controlled for other variables and filtered them all so that their p-values were 0.001 or less (in fact, of the ones below only “sweets and desserts” is p-value 0.001, all the others are below that). Nothing too surprising, but the magnitude of effect of french fries was pretty large:

I’m a big believer in not taking any given dietary study as gospel, and really doing a lot of personal self-experimentation in terms of your weight loss or gain. With those caveats in mind I think we can safely say that in the aggregate society would do a lot of good if we could decrease the consumption of soft-drinks and fries. That’s the “low hanging fruit.” I know many people who have given up soft-drinks, and it doesn’t seem like a change which is equivalent to going vegan or vegetarian, where back-sliding is very common.


Comments (28)

  1. Do you have a lifestyle chart as well?

  2. John Emerson

    Single-factor pop explanations of anything health related are usually dodgy, especially when people try to put them into practice. *

    HFCS, for example, is harmful because it’s the cheapest sugar and is used in enormous quantities in lost of cheap and easily available foods. One spoonful of HFCS is more or less the same as one spoonful of honey, which is high fructose too**; it’s a matter of dosage. But many react as though HFCS were a toxin.

    My guess is that the health effects of food would cluster in lifestyles, SES’s, and personality types, and that improving diet would only work if it also involved a change of lifestyle and perhaps an improvement in emotional state (though changing diet could be a first step in that). And also that most of the fretting about diet is done by the people who least need to do so, like my former model-thin boss who ate one hamburger and talked about it for 2 or 3 days.

    * Many of the great triumphs of medicine are single-factor explanations, e.g. for smallpox, diabetes, ulcers, etc. My point is that these triumphs aren’t thick on the ground.

    ** Some say that impurities in HFCS, e.g. mercury, make it harmful. If they turn out to be right, then I’m wrong. But most of the anti-HFCS stuff I’ve read is so permeated with various agendas that I don’t trust it.

  3. Eating habits are influenced by the media, that is dirty.

  4. dave chamberlin

    I recall reading in the book “The Skeptical Environmentalist” that average calorie consumption per day in the United States has increased by 1000 calories since 1960. If true, and I can’t confirm it, that is insane. I sat waiting for someone to come out of a small town Walmart, because I can’t stand to be in those places, and having lots of time on my hands I started counting how many of the women coming out of the store over the age of 25 were overweight. Before the people I was with came out, nearly 100 women in this category had waddled past me and 80% of them were just plain fat.

  5. Cathy

    Actually, there is a wonderful web lecture out there called “The Hazards of Sugar” where a biochemist goes through the whole cycle of how fructose, glucose, and sucrose are broken down by the body, and comes to the conclusion that yes, fructose is a toxin. It is an hour well spent watching. The good news is that fiber is the “antitdote” to the poison, so as long as you’re consuming your sugar in a natural form (e.g. fruit, whole wheat bread), or in minimal quantities properly offset by other fiber sources (lots of vegetables), it won’t kill you.

    As for the study, the issue isn’t potatoes, it’s overly processed potatoes – fries and chips. Eat them baked or boiled and they’re very nutritious and filling. But portion control is key as well, and you can’t overload them with sour cream and butter.

  6. Lemniscate

    It’s worth noting that not all weight change is related to fat mass. People gain and lose muscle mass as well. This is often not taken account of when meat intake is considered, as higher meat intake is associated with increased muscle mass, especially in active people. People on certain diets may also lose muscle mass due to protein deficiency.

  7. We are given the illusion that multiple types of happiness may be had simultaneously when they are not really compatible at all.

    The pleasure of having a healthy, thin body is not compatible with eating a highly processed diet, nor with being sedentary, nor with getting rid of one’s cognitive surplus with television. Yet, going without highly concentrated food when cues of its availability are all around one, and exercising when that is not the social norm, and avoiding television when it cures the average person’s loneliness and boredom so effectively, are extremely difficult to do – they mean suffering for most people – and require immense personal discipline that is beyond the capability of most of us monkeys. It’s a systems problem. But we don’t like to admit that misery is guaranteed.

  8. omar

    Low hanging fruit…and still surprisingly under-appreciated. Soda pop and most “energy drinks are the most insane food choice out there. Just eliminating soda and fries will not fix everything but it will have an impact and its relatively easy to do. I do suspect that most of the benefit will be in prevention and the impact may be less in terms of reducing weight in those already overweight. This is because soda and fries are loaded with more calories than most people think they have, and their hedonistic appeal can lead to excessive intake and messes up our imperfect “weight maintenance” circuits. Once weight has been gained and has stuck around for a while, then its hard to take it off even if you stop the fries and soda….it seems that we have multiple systems that work to hold on to fat and few that work hard to reduce weight to some ideal level. Which makes sense from an evolutionary point of view (in an environment of scarcity, why bother to evolve systems to reduce weight?). Still, a society wide effort to limit soda and fries should still have a positive impact. Definitely needs to be publicized (the readers of this blog may know all about the calorie content of cans of coke, but you would be surprised at how surprised most of my patients are to learn that one can of coke has 9 spoons of sugar in it).

  9. @Dave;
    When I looked at this issue last year the reference I found was that average caloric intake has increased by 600 to 700 Cal since 1970.

  10. Nick Patterson

    In this kind of study there is a massive confounding effect. If it is widely
    believed that food X is bad for your health, then it follows that people who
    eat lots of food X are not so careful about their health. Unsurprisingly it will then
    turn out that those who eat X are less healthy.

  11. Khadijah

    I totally agree with you on personal self-experimentation. We all have different body types, gut bacteria and what not. If people just took more responsibility for their own health and diet, and take responsibility for your own choice and the things you put in your bodies, seriously… I don’t believe that the answer lies in going vegan/paleo/south beach or whatever. Its your body. Live or die don’t blame the doctor or Mc Donalds or the tobacco company or the school lunch.

    Personally, I constantly get criticized for not eating breakfast, never snack outside of mealtimes. I’m no skinny btch but I’m slender and ‘average’ for an asian and eating breakfast does increase my appetite throughout the day and causes me to consume more calories than I need or want. So I skip it. “OH ITS SO UNHEALTHY FOR YOUR METABOLISM ITS ABNORMAL” says the overweight chick who’s snacking on carrot sticks at 10am and eats a handful of almonds at 3pm… Hey if that’s working out for you good for you.

  12. Andrew Lancaster

    Shame they did not split up the alcoholic beverages to see if for example wine and beer have different effects.

  13. John Emerson

    Cathy, if you look at the graph, it’s the potatoes. Chips and fries are the worst, but on the chart, potatoes are bad.

    I would take the “fructose is a toxin” people more seriously if they weren’t often the same people who tell us about the magical health effects of honey. Honey is high-fructose. My opinion remains that it’s ALL in portion control, and moderate amounts of dextrose, glucose, sucrose, or fructose, refined or in natural form, aren’t bad for you. There may be marginal problems with fructose compared to the others, but fructose isn’t a toxin. Few foods are all good in any amount, and over the last 40 years I’ve heard a parade of fanatics talking about how this or that food is evil.

  14. Sean Rutledge

    Increased calories from the study:

    In addition, our findings were broadly consistent with cross-sectional national trends with respect to diet and obesity: between 1971 and 2004, the average dietary intake of calories in the United States increased by 22% among women and by 10% among men, primarily owing to the increased consumption of refined carbohydrates, starches, and sugar-sweetened beverages.

  15. on a personal note, i kind of lived the life of a carb-binging programmer 2000-2002, and went up to 165 lbs, from 135 lbs when i was a freshmen in college. i stopped the carb binging and came down to the 150-160 range from 2003-2007, increased my activity and upped protein (nuts, etc.) consumption, and have been 140-150 from 2007-2011. i have soft drinks a few times a year (there’s a burger place i go to where the water is always lukewarm and i eat habaneros with my burgers, so i need something to neutralize afterward….). instead of a big change my strategy has been a series of moderate changes which i can internalize.

  16. Rich

    I was diagnosed with type 2 diabetes about 2 years ago. To control by blood sugar levels, I immediately cut back on the “white stuff” in my diet. That is, I stopped eating most foods with added sugar and starches such as potatoes, bread, rice, pasta, etc. Besides seeing a drop in blood sugar levels, I lost 45 pounds and my blood pressure dropped to a healthy 110/75 without pills.

    I’m no longer surprised by the source of health problems in America. Cheap, but unhealthy carbs, seem to be everywhere. Even my local drugstore has a “food” department which is mostly stocked with foods made from sugar and refined starches.

  17. John Emerson

    Jeez, Razib, you aren’t turning this into a diet and health site I hope.

  18. Richard Harper

    Potatoes are one of the absolute worst foods for cooking in an iron skillet in terms of absorbing lots and lots of the grease/oil/butter that is keeping the foods from sticking. I now have a very direct sense that french fries are a whole lot of grease and some small amount of potato. Now when I do have potatoes, I boil them first and add to the skillet meal as the very last step.

  19. John

    Could the argument for french fries be that most people eat tons of ketchup (contains high fructose corn syrup) with them?

    HFCS linked to obesity among other conditions

  20. dave chamberlin

    If sin taxes were levied on harm the product causes there would be as steep a tax on all the sugary delights comparable to cigarettes and liquor. Fat chance, as long as politicians such as US Senators need to raise $20,000.00 dollars a day to get reelected, they have absolutely no choice but sell out the public good for campaign donations from special interest groups. No rant or ideology in that political statement, just fact.

  21. Dwight E. Howell

    Not enough exercise is at the top of my list. Eating when not hungry is a second factor. I do like potato wedges but they aren’t daily. I’ve even tried making my own using a microwave with a little oil and a lot of spice but I’m not sure it matters. One thing that will kill my munchies is about a teaspoon full of olive oil. I have often wondered if a craving for fat/oil is why I was actually eating.

  22. Anthony

    John – if you’re a believer in the paleo/Atkins/low-carb sort of diet, french fries are awful because they’re easily-digestible starch-sticks. If you’re a believer in the Ornish/conventional/low-fat sort of diet, french fries are awful because they absorb tons of oil. No HFCS needed to make them bad news.

  23. toto

    If it is widely believed that food X is bad for your health, then it follows that people who
    eat lots of food X are not so careful about their health.

    I suspect that the negative effect of whole grain is related to this.

  24. John Emerson

    My guess is that there’s a behavioral cluster involving lack of exercise, lots of TV, snacking between meals, and cheap fast food which accounts for one large chunk of the obesity. HFCS, fried foods, and potato products are in the food that these people eat because they’re the cheapest forms of starch and sugar. Someone else eating small amounts of all these foods would suffer no harm. Part of the problem is that fast foods are engineered to cause craving.

    I’ve been arguing this for years, that there’s no miracle food and no satanic food, and as long as you get enough of everything and not too much of anything you’re OK. There are foods that make this balance easier to find, to be sure, and there are others that tend toward abuse and overeating (and which also don’t provide key nutrients), but the abuse and lack of balance is the problem.

    I think that a lot of the energy behind the idea that some foods are magic and some satanic comes from people selling diet programs.

  25. ackbark

    I saw something to the effect that the fructose in HFCS is a different molecule from the fructose found naturally in fruits and vegetables, and honey, and that the natural form is always bound to either glucose or pectin so the body responds as if it were glucose or pectin, while in HFCS it isn’t bound to anything and the body responds entirely differently. (Fructose L in HFCS vs. fructose D in nature).

    Additionally most fruit juice is refined so the pectin is stripped away leaving the fructose to it’s own devices.

  26. John Emerson

    The two wiki articles I looked at (HFCS and fructose) were inconclusive but mostly negative on the claims about health, with the exception of the possibility of mercury contamination. The science in health advocacy writing can be really random.

  27. I haven’t eaten fast food in 2 years, and I have no plans to ever eat it again. I do love me some sugary soda, though.

  28. L

    Within each 4-year period, participants gained an average of 3.35 lb

    That’s an extra 8cal/day or an extra can of coke every 17.5 days, to put it in perspective.


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About Razib Khan

I have degrees in biology and biochemistry, a passion for genetics, history, and philosophy, and shrimp is my favorite food. In relation to nationality I'm a American Northwesterner, in politics I'm a reactionary, and as for religion I have none (I'm an atheist). If you want to know more, see the links at


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