Decades ago, when I began my exploration of obesity,
I was firmly in the vegan, total-vegetarian camp. Because of my cultural upbringing, I was accustomed to a plant-based dietary lifestyle, and so I pursued the assumptions of this dietary style in my early studies.
I grew up on the campus of a religious college that taught, served, and ate only a plant-based diet plus milk and eggs. Since the lacto-ovo vegetarian diet was the only diet that I knew, it was somewhat shocking and disgusting to think that people ate animals. The only meat I saw was served to my Cocker Spaniel, “Sneezer.” He got a serving of meat from a can every day; otherwise, he just ate the scraps from our vegetarian table. But he was a dog, and I was a human, and I was told that humans who ate vegetables were the healthiest.
Then, in medical school, I learned that humans are designed to eat all kinds of foods. We have “eye teeth” for ripping and tearing flesh. We have a gallbladder that serves as a reserve that can provide a large dose of bile to digest high-fat meals that don’t come from vegetables. In epidemiological classes, we looked at eating habits across the globe. What a wide variation!
It became increasingly clear that humans adapted to the environment they were in. If they lived near the sea, foods from the sea became their diet. If they lived in the ice-locked extremes of the Arctic Circle, they ate a lot of animals because there weren’t many carrots and snap peas around. If they lived in the Middle East, they adapted to grains and legumes.
Whether from our genetics, our environment, or because of ethical commitments, some choose not to eat the fats and proteins coming from animals. Some religions make the vegetarian lifestyle an integral part of their belief system. For instance, people who are born to the ancient religions of India such as Jainism, Hinduism, and Buddhism, will not eat foods that come from an animal. Those from the Abrahamic religions (Judaism, Christianity, and Islam) have groups of believers who encourage plant based diets because of the health, ecological, or ethical ramifications. They also restrict the use of foods that are designated as “ceremonially unclean” such as pork, bottom dwelling fish, and mollusks.
My own Health Sciences University, which was developed by a branch of the Protestant movement, the Seventh-day Adventists, strongly encourages plant based diets. In fact, the lacto-ovo vegetarian diet is all that is available to the students and staff when eating in the University food services. Patients in the hospital can choose meat dishes if they desire, but institutionally, the University promotes plant based diets.
Currently, about 7% of the American population report that they are following a vegetarian diet that allows milk and eggs but no meat, including fish and fowl. Another 2% of our population eat only plant-based foods with no milk, milk products, or eggs.
In the science of human behavior we have two ways to study people. One is to just watch what they do on their own. They are not given any specific diet or lifestyle intervention. We call this form of study, observational or epidemiological. When we observe these natural behaviors we can collect this information and statistically make some correlations or hypotheses. These relationships do not “prove” cause and effect but they “suggest” a possible connection.
The second form of study is more intentional. We take a group of people that consent to be part of a study in which they will be randomly assigned to one intervention or another. Pharmaceutical companies are required to do this type of study to “prove” whether the drug or the placebo are more effective at, say, lowering blood pressures or some other desired effect.
Using the first kind of study, observational, it has been well documented that populations of people that eat largely vegetarian diets have less obesity, heart disease, diabetes, hypertension, and many cancers. We can ask ourselves whether this is observed because of the lifestyle that they follow or are the people that chose this dietary lifestyle biologically different than those that chose to eat all kinds of foods.
These questions can be better answered when we use the second type of study, an interventional randomized controlled study. So we ask for volunteers from a population of people who are accustomed to eating all types of foods and ask them if they would be willing to be randomized to continuing their usual diet or using the vegetarian diet we are studying. This type of study is more likely to get at the root of the specific question, “is the vegetarian diet better than having a diet that comes from both plants and animal sources?” The interventional type of study has done more to form the science behind what we are talking about in this book. One size does not fit everyone. Some individuals do very well with the vegetarian diet but some may find that this diet which is naturally higher in carbohydrates may become “fattening” and find that they now crave foods that previously were not a problem.
This actually happened to one of my patients. She was at a healthy weight when she decided to become a Seventh-day Adventist. Even though a lacto-ov0 vegetarian diet is not a “tenant of faith,” it is highly recommended in this denomination. Being dedicated to her new spiritual path, she became a vegetarian. But the diet did not fit her biology. She began to crave sugar and refined starches. In a relatively short time, she had gained 40 pounds.
I helped her return to a diet that included fish and fowl. Her cravings decreased, and she began to lose weight. Soon, she was back into the healthy weight range.
Within an observational or epidemiological study of close to 100,000 Seventh-day Adventists, it was observed that one third of those who followed the vegan or total vegetarian diet were overweight or obese. Again, this does not prove that the diet caused obesity, but we still must accept that the vegetarian diet may not protect everyone from obesity. We must take each person’s situation separately and adjust the lifestyle to accommodate for their individual reality.
It may be difficult for a person who has avoided meat all their lives to make the change to healthy animal proteins. At the very least, we must find a way to limit refined or processed grain-based foods, and look for ways to put healthy fats and proteins in their diets.
It’s important to remember that it is the refined grains that are the most addictive, and they have the least amount of appetite-suppressing fiber. Even so, some overweight people will find that even whole grains and potatoes can be addicting. As frustrating as it may be, we must work with the biology that is unique to us and the environment we find ourselves in.
Is it possible for a largely vegetarian diet to be “low carb”? The answer is yes. You will remember that in chapter 25 we taught you to count “net carbs” not calories. You can subtract the fiber and sugar alcohol grams from the total grams of carbohydrates. For a vegetarian, a low carb diet would mean eliminating or a least drastically reducing all refined processed grains and free sugars.
Which brings us to pastas, and there’s some good news here. Pasta is usually made from high-protein wheats, like the “Montana Red” variety. Some pastas are enriched with egg, which lowers the glycemic index and increases the protein content. It is also possible to get pasta made from edamame or young green soy beans. This makes it easier to have entrees that are lower in net carbs.
Then there is the issue of fruit. Tropical fruits generally have high glycemic loads, which means they will cause a spike in blood sugar and thus increase insulin. If a person is already insulin resistant and overweight, this isn’t good. A better choice would be berries, which tend to have lower glycemic loads. So we are now looking at strawberries, raspberries, black berries, and all the way to the “super food” blue berries. So, let’s say that our goal is 50 to 60 net carbs per day. It would be possible to gain our protein from eggs and cheeses along with lentils, soy and black beans. We could use an abundance of healthy fats from olives, avocado, nuts, and seeds along with an abundance of non-starchy vegetables such as string beans, asparagus, deep colored greens, tomatoes, and peppers.
While we’re talking about vegetables, let me say something about the quality of those plant foods. In my earlier ignorance, I used to tell my patients that if the plant grew, it must have all the necessary nutrients. I could not have been more wrong!
The British seem to care more about the nutrients in their foods than we do. They have tracked the nutrient content of our vegetables during the modern revolution from small farm gardens that are cultivated with plenty of manure and compost to our current “agribiz” food factories. Yes, the vegetables still grow in dirt, but what nutrients are in that dirt? According to our English friends, broccoli today has 40% less calcium that it did four decades ago. It looks the same, tastes the same, and feels the same, but those florets have fewer nutrient than they did a few years ago.
So what can we do? Organic food will have more nutrients because farmers won’t be relying on chemicals. But will they use enough manure and compost to return enough nutrients to the produce? Also, organic food does cost more. It may put a strain on your budget if you eat only organic foods.
This means, for most of us, we will probably want high quality vitamin and mineral supplements. While some enthusiastic vegans decry the need for supplementation, it has been my experience that adding B vitamins and calcium is prudent. It is a simple matter to measure B vitamins with a blood sample. By contrast, the blood level of calcium is not an adequate test because our bodies strive to maintain these blood levels stable to do such things as keeping our hearts beating. Your body will pull calcium from your bones to make sure these levels are stable. This means that you won’t know you have a calcium deficiency until osteoporosis sets in. At that point, there won’t be much you can do without pharmaceutical intervention.
So what is the summary? If you are a healthy lacto-ovo vegetarian and do not have a weight problem, or are not diabetic or pre-diabetic, please continue eating this way. It is a healthy diet plan. If you are following a vegan diet plan, remember to supplement the nutrients that are not in your diet.
If, however, you are following a vegetarian dietary plan and find yourself becoming unhealthy with extra weight and non-optimal laboratory risk factors, please get some help. You have become part of the Clash. Your biology is not fitting your current environment. You will need to find a way to accommodate the Clash. That may be through adding more proteins and fats into your diet, or considering other types of accommodation that you will be reading about in subsequent chapters.