Will a return to home cooking bring America’s salt problem under control?

Is home cooking the key to America’s health problems? We are suffering an obesity epidemic and from a wave of chronic diseases. The problem, we are told, is too much fast food and too much processed food. The solution appears to be simple—go back to home cooking. Two reports have come out in recent years that seem to support this contention, particularly with respect to overconsumption of sodium. Can we solve health problems associated with food merely by reviving cooking skills? Or is the recent push to do more cooking at home merely another way men are telling women to work harder?

Hello pork zucchini and potatoes

In books, news stories, cooking shows, ads for home meal-kits and elsewhere in social media we are encouraged to avoid fast and processed food and cook our own meals. Home cooking is proclaimed as healthier and more sustainable than processed food and dining-out opportunities. Our reliance on food prepared outside the home is getting blamed for the obesity epidemic. I believe that most of our health problems associated with food derive from eating too much and eating too much of the wrong kinds of food. Having said that, I reiterate, not all processed food is junk and not all junk food is processed.

Most of the salt we consume comes from food purchased outside the home. A recent journal article that 71% of the sodium we consume is from processed and restaurant foods and NOT from adding salt at the table or during cooking. In this study, the researchers separate out sodium

  • added at the table,
  • added in home food preparation,
  • inherent in the food, and
  • added outside the home (restaurant and processed food).

This study (1) was very thorough, looking at a wide range of subjects from three distinctly different geographical regions of the USA. They did follow-ups to verify that their data were adequate. I do not question the accuracy of their results. It would have been nice, however, if they could have separated the amount of sodium added in restaurants from the amount added to processed food consumed in the home. It would have also been interesting to see if there was a difference in the amount of salt added in fast-food restaurants vs. that in all other restaurants.

Most of the food we eat at home is highly processed or moderately processed. The other study (2) found that 77% of the foods we eat at home are either highly processed (61%) or moderately processed (16%). These figures include processed ingredients we use to prepare foods at home. Not surprisingly, the more highly processed foods were higher in sodium than those less processed. The investigators also separated out foods that

  • were ready to eat,
  • were ready to heat, or
  • required preparation or cooking.

The ready to heat (such as microwavable, frozen meals) were the highest contributors to sodium consumption with the ready to eat (including fresh fruits) in between the food requiring preparation or cooking. This study also seemed well designed even if it did not consider restaurant foods. My main contention with the study is that it seemed to classify almost everything we eat as a highly processed food.

And what are some of these highly processed foods? Any bread product, sausages or lunch meats, frozen meals or vegetables, and ice cream are among those listed. Highly processed ingredients include salsa, jelly, refined grains (flour), mayonnaise and any other condiments. Moderately processed items include plant-based milks; seasoned refrigerated, frozen or canned meats, cheese, flavored yogurt, and salted butter. So, what is left? Plain milk; eggs; unsweetened fruit juices; fresh, frozen and dried fruits; fresh vegetables; plain nuts; plain yogurt; and unseasoned meats. Ingredients that are either not processed or minimally processed include honey, spices, table sugar, pure maple syrup and table salt.

The take-home lesson from the first study (1) is that little salt is being added during cooking or at the table. The solution proposed is not to cook more meals at home. Rather, the article suggests that sodium be reduced in commercially processed foods. It encourages consumers to purchase low-sodium versions when possible, but consumers tend to associate low sodium with poor flavor. The take-home lesson from the second study (2) is that most of the food we eat is either highly or moderately processed and that these products are contributing to overconsumption of saturated fat, sugar and salt. By putting both studies together, I conclude that the reason most salt is not added in home is that most of the food we eat at home is processed in one way or another. I like the idea that the second study actually classifies processed foods. I do think, however, that their classification of highly processed is overly broad and unhelpful in informing us of how to decrease sodium in our diet.

It is not clear, to me at least, that a marked reduction in processed food would necessarily lead to a marked reduction in sodium consumption. More home-prepared meals could lead to recipes with more added salt. The meat, potato, two vegetable, desert meal I grew up on would probably not be sufficient to please most millennial palates, at least not for numerous meals a week. Creative cooks looking to expand their menu options would probably search for recipes that contain sauces, a rich source of sodium, to replace those frozen, microwavable dinners. The “fresh” meals provided by meal kits at $10.00 a plate provide more sodium than most of us would expect in truly home-cooked meals. That is because many of the ingredients in these meals would fall into the highly processed category.

HF Salt

Nutritional values for a meal from Hello Fresh. Note the amount of sodium and number of ingredients present. Individual meals ranged from 20 to 64 % Daily Value for sodium.

Delving into the first study and doing some calculations, I concluded that merely expanding the unprocessed dishes would likely lead to deficiencies in sodium as sodium is an essential mineral. The problem is that salt-sensitive Americans consume too much sodium and will search it out where they can. I do not think that it is a given that replacing processed meals with home-cooked meals would necessarily lead to major reductions in sodium consumption. When I view recipes on “healthy-eating” sights on the internet, I see relatively high levels of added salt, particularly when “highly processed” ingredients like hummus, ketchup, salsa, sour cream or soy sauce are included in the recipe.

Michael Pollan tells us in Cooked that we don’t have to worry about using salt in home-cooked meals if we just cut out processed foods. And yet, one serving of the recipe he provides for pork shoulder barbeque provides 40% of our daily value for sodium which then goes up to 57% if you add the suggested sauce. And, if the pork is that good, what is stopping a person from eating more than one serving? Am I cherry-picking one recipe? Yes. Am I being over-critical by suggesting that the serving size may not accurately reflect what a person would eat? Yes. Would a critic of processed food single-out a commercial product with this much sodium on its label as unhealthy? Probably. And would this critic go on to suggest that the serving size might not accurately reflect what a person might eat? Also, probably. Very few recipes I see online provide the daily value for sodium, and, I suspect, that most home cooks do not have any idea of how much sodium is present in a dish they prepare.

Sodium on sandwich

Graphic from https://www.cdc.gov/salt/reduce_sodium_tips.htm

Finally, consider the home-made turkey sandwich. Does it really represent home cooking or is it a highly processed food? And does it help lower sodium in the American diet? By the criteria used in the second study described above (2), the bread, deli turkey, slice of cheese and any condiments if purchased at a store would fit the definitions of highly processed foods or ingredients. The lettuce and tomato if added would qualify as unprocessed. Home-baked bread, home-made cheese from milk and home-roasted turkey could also be considered unprocessed. From this perspective, however, most home-made turkey sandwiches would qualify as a highly processed food assembled at home. According to the CDC, a typical home-made turkey sandwich could contribute 66% of our daily value for sodium. That certainly squares with the conclusion of the first study (1) that most of the sodium we consume comes from food in which the salt is added outside the home. But how many of us think of a home-made turkey sandwich as a highly processed food or a major source of sodium? The real world of food is more complex than it would appear.

References

(1) Harnack, L.J., M.E. Cogswell, J.M. Shikany, C.D. Gardner, C. Gillespie, C.M. Loria, X. Zhou, K. Yuan and L.M. Steffen, 2017. Sources of sodium in US adults from 3 geographic regions. Circulation 135:1775-1783.

(2) Poti, J.M., M.A. Mendez, S.W. Ng and B.M. Popkin, 2015. Is the degree of food processing and convenience linked with the nutritional quality of foods purchased by US households? American Journal of Clinical Nutrition 101: 1251-1262.

Next week: Nutritionism: The Science and Politics of Dietary Advice

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