As a practicing primary care physician, I was aware that diet affected heath and spent time counseling people about diet: the DASH diet for hypertension, low fat for elevated lipids, calorie control for overweight, etc. As the planet struggles to support a population that will hit 9 billion by 2050 (adding the equivalent of 2 more “Chinas” by then), and obesity is an epidemic that means our children will have shorter lives than their parents, attention to what constitutes good food and how we produce it is rising.
Not long ago I explored what we are learning about the microbiome we all carry and finding that our gut bacteria strongly impacts our health, how we digest food, and how what we eat changes our bacteria. This month, Scientific American devotes an entire issue to the topic of food and launches a food blog.
Below I share some of the amazing research I discovered:
• There is the idea that to tame invasive species we should feed them to the world’s biggest predator, humans. Bun Lai, a chef in New Haven, serves invasive species in a variety of innovative dishes like European green crabs and flat oysters. Others prepare lionfish, kudzu, and feral hogs. For more on the interesting idea for feeding the planet and improving the environment, go to http://eattheinvaders.org/
• The emerging connection between research on our microbiome and the prevalence of obesity and other illnesses is making us question our fundamental thinking about weight and health. The ‘energy imbalance’ theory of weight gain (that I used in my medical practice for 25 years) is pretty simple: humans gain weight when we eat more calories than we burn. Now there is research that causes us to question this idea. First, there is evidence that hormone imbalance contributes to obesity. Simplistically, this theory says that the ingestion of a diet high in carbohydrates stimulates insulin and causes fat cell metabolism to change, which stores more fat. The entire literature on the number of calories contained in various foods is based on 19th century laboratory science that we now know is, at a minimum, too simplistic.
• As noted by Biologist Rob Dunn in Scientific American, “to accurately calculate the total calories that someone gets out of a given food, you would have to take into account a dizzying array of factors, including whether that food has evolved to survive digestion; how boiling, baking, microwaving, or flambéing a food changes its structure and chemistry; how much energy the body expends to break down different kinds of food; and the extent to which the billions of bacteria in the gut aid human digestion and, conversely, steal some calories for themselves.”
• The research about the differences in microbiome between obese and non-obese individuals suggests that the bacteria in the guts of obese people are more efficient at metabolizing food, so instead of being lost as waste, more nutrients get into the bloodstream. And if the nutrients are unused, they are stored as fat. No practical implications are yet available, but it is known that changing one’s diet does change his or her microbiome.
Until we learn more about how our bacteria can be used to help us be healthier, we now understand better why processed foods are associated with obesity and raw food is associated with healthier and leaner outcomes. Dunn, the biologist, also noted that processed foods are so easily digested in the stomach and intestines that they give us a lot of energy for very little work. In contrast, veggies, nuts and whole grains make us sweat for our calories, generally offer far more vitamins and nutrients than processed items, and keep our gut bacteria happy.
So it would be logical for people who want to eat healthier and cut calories to favor whole and raw foods over highly processed foods. This supports Michael Pollan’s pithy advice to shop around the outside walls of the grocery store to avoid all those aisles of processed food
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