The Three Food Groups Perhaps you are thinking, didn’t we learn about four food groups in school? No, maybe it was five food groups? Regardless of what you may remember, you can thank Dr. Thomas Campbell, author of "The Campbell Plan," for a better method of selecting nutritious foods based on only three food groups. While no food grouping formula is perfect, Dr. Campbell’s method has in its favor simplicity with a high probability of identifying foods as nutritious or not nutritious. So, here are the three important food groups. 1. Animal products 2. Whole plants 3. Plant fragments (processed foods) To determine which category a food belongs in, you need only answer two questions. 1. Is this an animal product or a vegetable product? 2. If it is a plant, is it similar to what was originally grown? To help clarify the three food groups, consider cheese, doughnuts, and apples. Cheese is not a plant so it must be an animal product. A doughnut is not an animal and not similar to what grows naturally so it’s a plant fragment. An apple grows on a tree and thus belongs in the whole plant food group unless it is apple juice or applesauce and then it belongs to the plant fragment food group. Applesauce that included the apple peel could earn a place in the whole plant food group despite no longer looking like an apple. It’s pretty easy to identify animal foods and whole plant foods. What gets trickier is the much larger plant food fragment group which makes up close to 99% of the 30,000+ foods found in a large grocery store. To help reinforce the concept of food fragments, consider the lovely beet, so pretty, so purple, and so delicious. Unfortunately most only meet the beet as a plant fragment in the form of a white granular sugar. Most foods containing refined sugar, oil, or flour will land in the plant fragment group. In contrast, a can of beans or corn would usually fall into the whole plant food group. Of course, there are degrees of processing and at times a good call will require evaluating the ingredients. Most important is the ‘degree of wholeness.’ A food that’s 80% whole plants would, of course, be preferable to a food that is only 20% whole plants. Most importantly, be aware that eliminating almost any part of the edible fruit decreases the nutritional value. When too much of a plant’s nutrients have been removed it belongs to the plant fragment group. Packaged foods can be difficult to categorize. For example, a pizza has a flour crust (plant fragment), cheese (animal product), and a topping which could be a combination of whole plant and animal foods. Although there are healthy alternatives, pizzas typically end up being mostly plant fragments and animal product While the three food group approach may seem too simple to be practical, it actually serves several very useful purposes. The first of these purposes is to downplay the importance of calorie counting and selection based on macronutrients (fats, carbohydrates, and protein.) Granted, these are relevant issues. What is more important is the way the body utilizes food. When we eat food fragments and animal products we tend to gain weight while also minimizing our opportunity to utilize fiber and absorb micronutrients. In contrast, when we eat a whole plant food that hasn’t been reduced to plant fragments, our digestive system tends to absorb the macronutrients and micronutrients as needed so long as our diet includes a reasonable variety of plant foods. While animal foods do provide protein, for most (even athletes) this is often excessive protein that reduces the opportunity for daily consumption of micronutrients, reduces daily consumption of fiber and increases daily consumption of cholesterol. As a rule of thumb, if eating enough plant food to obtain the daily calories needed, whole plant foods will provide an adequate amount of carbohydrates, protein, and fat without the need for any supplements. Granted, this can be a challenging idea if you have lived through a lifetime of nutrition guideline propaganda dictated by the Department of Agriculture along with the massive barrage of advertising that comes compliments of the meat and dairy industries. The value of the three food groups is perhaps best understood by comparing the major dietary approaches. For example, in the Standard American Diet (SAD), animal foods provide about 45% of the calories, plant parts (processed foods) about 45% and whole plant foods about 10%. In contrast, low-carbohydrate diets like the Atkins and South Beach diet are typically about 70% animal foods, 15% refined plant foods (plant parts) with perhaps 15% whole plant foods. Unfortunately, the high protein content comes with significant health concerns, not the least of which is increased risk for diabetes, heart disease, and cancer. The low fiber content is also counterproductive to creating a healthy gut microbiome and of course, the low level of micronutrients only adds more problems. Fortunately, few adhere to these diets for long. For most, it’s a quick way to lose a few pounds. Unfortunately, less than 2% manage to keep the weight off for 3 years. In other words, for most, it’s another yo-yo diet that’ s likely to disappoint Vegetarian diets are another approach to selecting food. Although vegetarian diets exclude animal meat they often include animal food in the form of dairy products (milk, cheese, yogurt, etc.). Some vegetarian diets also include eggs or fish. Typical vegetarian diets are about 35% animal foods, 45% refined plant foods (plant parts) and about 20% whole plant foods. This proportion of the three food groups puts the typical vegetarian diet ahead of the Standard American Diet. Although not the norm, a vegetarian diet low in dairy and higher in whole plant food would be a very nutritious diet. In contrast, some vegetarians follow a diet that’s very low in whole foods. In that case, a vegetarian diet may be no better than the Standard American Diet. A diet that contains no animal foods is called a vegan diet. The vegan diet has the advantage of having no cholesterol, plenty of fiber, plenty of micronutrients, and a nice balance of protein, fat, and carbohydrate. Unfortunately, like vegetarians, vegans can also find ways to choose foods that meet the definition but not the requirements for good nutrition. The abundance of processed foods available offers many pitfalls for the unsuspecting shopper. Vegan candy, vegan soft drinks, vegan desserts, and more await those wandering the aisles of almost any food store. A typical unhealthy vegan diet could easily be 75% refined plant food (food parts) and perhaps only 25% of whole plant foods. In contrast, a healthy vegan diet would need at least 75% whole plant foods and 25% or less refined plant foods. While the healthy vegan diet is the best diet discussed so far, it is not the optimal diet. The optimal diet would be one that further minimizes refined foods to the point that the diet included almost all whole plant foods. For some, avoiding all animal foods and refined plant foods may be impossible. Fortunately, for the healthy, small amounts of animal products are unlikely to have a significant effect on health. The exception is for people with advanced disease states. For example, in the cases of heart disease, reversal of the condition has only been observed with a near perfect plant-based whole food diet. Most popular diets are similar to one of the seven diet types discussed here. Regrettably, few appreciate the merits of assessing these diets by the three food group test and end up with an unhealthy and unsustainable version of the diet. What often goes unsaid in promoting diets is that being better than the Standard American Diet (SAD) is not saying much. The Mediterranean diet which comes close to the vegetarian diet is a typical example. While the Mediterranean diet is definitely better than the Standard American Diet, it still comes in far behind a quality plant-based whole food diet. Refined Whole Animal Diet Type Plant Plant Food ======================================== Standard American 45% 10% 45% Low-Carbohydrate 15% 15% 70% Unhealthy Vegetarian 45% 10% 45% Vegetarian 45% 20% 35% Unhealthy Vegan 75% 25% 0% Healthy Vegan 25% 75% 0% Optimal Minimize Maximize Minimize Having a framework for understanding the differences between popular diets may leave you wondering if humans were really meant to be vegans. Historically there have been few cultures where people ate no animal foods. However, among cultures with the longest life and best health on into old age, their diet was predominantly plant-based whole foods. The dilemma with including animal products today is that as one moves up the food chain to larger animals (cows, pigs, fish, chickens, etc.) the quality of animal foods is much lower than in the past. Often the quality of animal products is compromised by environmental toxins, weed killers, antibiotics, and growth hormones. A large animal that has eaten a ton of plant food may have concentrated the toxins in that ton of food into their body. In contrast, you could obtain comparable nutrition from a few pounds of plant foods and thereby ingest only a fraction of the harmful toxins. Unfortunately, even pasture-raised meats are questionable since many toxins are in the general environment and unavoidable. When advising patients to eat a small amount of animal food, the question of what small means is often misunderstood. In cultures that had the best health outcomes, animal meat was for special occasions or if used more often, then only used in small quantities as a flavoring. As a doctor, I often encounter patients that have an interest in improving their diet but question giving up all meat and other animal foods. For the healthiest of these patients, my advice is to minimize animal foods as a preventative measure that has the best evidence for good health. For patients that have developed chronic or acute conditions, I remind that the best evidence shows remission is possible but only with a nutritious vegan diet. For most, adopting a vegan diet requires time to develop new habits. A gradual transition built on small success is usually the best approach. Thus far, there are no studies that prove that a very small amount of animal products in the diet is better than none at all for healthy people. However, given that even small amounts of animal protein can produce observable inflammation, my recommendation for prevention and reversal of lifestyle-related chronic disease is eating predominantly from a variety of minimally processed vegetables, fruits, whole grains, legumes, nuts, and seeds. While an explanation of what needs to be in the optimal diet is pretty straightforward, getting there is not always so simple if coming from the Standard American Diet (SAD). The foods we eat are influenced by our emotions, education, home life, cooking skills, culture, our degree of food addiction, and more. Don’t despair if changes in your food habits come slowly. Setting modest goals is an important first step. It gets easier with each step. Just remember that taste is acquired through exposure to new foods. To help you on your way there is an abundance of excellent cookbooks that provide easy recipes for the novice and more advanced recipe books for you if that’s your cooking style. Should you need an encouraging idea, just let me know. Nancy Neighbors, MD Huntsville, Alabama "Health may not be everything but without health everything is nothing" - Dr. Hans Diehl |