Dispelling nutrition myths, ranting, and occasionally, raving


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A bit more about food combining

PB&B sandwich photo by Kevin Reese. Used under a Creative Commons Licence.

PB&B sandwich photo by Kevin Reese. Used under a Creative Commons Licence.

After I wrote about the utter nonsense of food combining last week I had a reader contact me to suggest that perhaps I could elaborate on the positive side of food combining. To be clear, this is not what is traditionally meant by “food combining” which is a complicated way of eating which erroneously is believed to aid digestion and is more based on not eating certain foods in conjunction with others than with eating a variety of foods together.

I mentioned in my previous post that combining some foods can be beneficial in terms of absorption. Fat soluble vitamins (ADEK) need to be consumed with fat in order to be absorbed. This is one of the many reasons that a low-fat diet has been decried by dietitians. Skimmed milk with added vitamin D? No sense to it unless you’re washing down a croissant (or an avocado, nuts, or other fat-containing food of your choice).

In addition to aiding absorption of fat-soluble vitamins, certain foods can help with the absorption of other nutrients. Foods containing vitamin C can help with the absorption of iron, particularly from plant foods in which the iron is less bioavailable than in meats. For example, eating peppers with your spinach salad can help you to absorb more iron. Or having an orange with your oatmeal, tomatoes and beans, etc. Of course, there are also instances where nutrients can hinder the absorption of other nutrients. Tannins and fibre may decrease the absorption of some minerals and medications. Oxalate (found in spinach and some other fruits and vegetables) can impede the absorption of calcium.

As my astute reader pointed out, there’s also the benefit of glycemic control imparted by eating certain foods together. As any reader of Wheat Belly can (and likely will) point out to you, whole wheat bread has a higher glycemic index than white sugar. The thing that’s not taken into consideration when latching onto that fact is that we rarely eat whole wheat bread in isolation. Turn your bread into a peanut butter and banana sandwich or chicken salad sandwich and you’ve altered the glycemic load of the meal because you’ve added other macronutrients. Consuming fat, protein, or fibre can all help to mitigate the effect of carbohydrates on blood sugar. This is why, if someone with diabetes is experiencing low blood sugar it’s much better to give them candy or juice than a chocolate bar. On the flip-side, this is why most dietitians will recommend that you consume two food groups at snacks. Having a piece of fruit and a few nuts or cheese and crackers, berries and yoghurt, veggies and hummus… will help to prevent a spike in your blood sugar and keep you feeling full for longer that if you were to just have a piece of fruit. It also helps you to meet your nutrient needs if you include a vegetable or fruit as part of your snack.


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Food combining

Photo by Tom Ipri on flickr used under a Creative Commons Licence

Photo by Tom Ipri on flickr used under a Creative Commons Licence

Not long ago I had the pleasure(?) of overhearing a conversation about digestion over a meal. One woman was explaining why she wasn’t having carbs at her her meal (this despite the fact that the hummus she ate certainly contain carbohydrate, as did some of the vegetables with her meal). Her logic was that to aid digestion it’s better to consume food groups separately. Hence, she was just eating vegetables and meat. Someone else piped in that this made sense and added that eating foods in a specific order must also be beneficial. I did my best not to bite off my tongue and eat it along with my vegetables, meat, and (gasp!) rice.

Not everyone knows about how digestion works and I can see how these myths perpetuate. But please give your body some credit; it can handle more than one macronutrient at a time.

I’ve addressed the issues of food “layering” and combining before. Just a quick reminder: digestion starts in the mouth with amylase breaking down starches. Your stomach does an excellent job of churning all of the food you eat, breaking it down, and making it into an acidic stew. Believe me, nothing is sitting in there on top of everything fermenting. Most of nutrient absorption occurs in the intestine. Consuming more than one food at a time may actually aid in nutrient absorption as some nutrients, such as the fat soluble vitamins ADEK, need other nutrients to be absorbed (in this case fat).

This doesn’t even address the fact that many foods taste better together. Think: chocolate and peanut butter, apples and cheese, bread and butter. There’s no need to deny yourself the pleasure of these foods. Variety is the spice of life and choosing healthy foods is complicated enough without adding the element of what to eat with (or without) something else.