As a kid, I remember waking up, getting ready for school, and heading downstairs to have my giant bowl of heart-healthy grain-based cereal. My parents would never allow me to have the sugary stuff because it was “bad,” instead, they would turn to the “healthy” cereals. Often meals would center around pasta, bread, and other grain-based products allowing for the food pyramid prescribed 11-16 servings of grains required to keep people healthy.

Looking back on this time, I do not find fault in my parents, but rather those that created dietary guidelines. That is why today, we will explore why whole grains are the worst carb people can eat for weight loss.

As humans, we have used grains as a source of nutrition since the time of Homo neanderthalensis. Archeologists have discovered grains in the teeth of our ancestors, thus informing us that humans ate grains and that humans can consume grains. However, it was not until the time of the fertile crescent when humans used grains as a staple food product.

The main reason at that time was scarcity. During the winter months, grains could be harvested and stored for the winter, thus providing a stable energy source for ancient humankind. Yet even though we created refrigeration and were able to keep virtually any food for an almost unlimited duration of time, we continued to use grains as a stable food source.

Another large pro-grain pus occurred with the seven-country study led by Ancel Keys, which essentially demonized fats (with relatively insufficient quality evidence), thus birthing the food pyramid we all grew up loving. This study has led to decades of clinical research evaluating whole grains, particularly for improving heart health.  

So what are whole grains?

Whole grains include all component of the grain as below:

• bran (outer fibrin layer with vitamin B)
• germ (core rich in vitamin B and E)
• endosperm (starchy middle with carbohydrate and protein)

Now grains also can include or exclude gluten. Gluten is a protein found in wheat, rye, and barley grains. Grains without gluten include quinoa, oats, amaranth, bulgur.

These grains are not bad for you in a solo format. However, when you consider many other factors, they may even be harmful to your health.

Why Whole Grains Are Good

As stated above, whole grains have been evaluated extensively in clinical research. Some potential benefits of whole grains include the following:

• 30% reduction in heart disease
• Reduce total and low-density cholesterol
• Reduce blood pressure
• Reduce weight
• Lower risk of diabetes

Yet when you dig deeper into these trials, I have found much information that can confound these findings.

First and foremost, the majority of these studies are observational and no randomized. An observational trial is where you evaluate a group of patients over time and look for outcomes, risk factors, etc.

On the other hand, randomized trials account for other factors at play and attempt to look at one single risk variable at a time. With that in mind, most observational and randomized trials looking at whole grains have not controlled for total calorie intake or additional healthy lifestyle factors like activity, mindfulness, etc. Thus, as many believe entire grains are a healthy lifestyle choice, they were more likely to stay active, reduce stress, and avoid alcohol and tobacco products.

As if that wasn’t enough of a confounder, studies use fiber interchangeably with grains and do not differentiate the percentage of the whole and processed grains used. Globally, these studies also had low compliance rates, leading to some issues with statistical power, therefore making it less likely for the results to be conclusive.

Now that we have evaluated that the potential benefits may not be as well-founded as previously expected, let us examine why whole grains may harm your health.

Calorie density

The rise of grains occurred during a time of scarcity and food instability. These foods served as a beneficial means for us as humans to thrive and subsequently a population boom. Since that time, we no longer strive to obtain calories for survival but rather have the opposite issue.

Foods now are packed with calories but not necessarily nutrients. Nutrients include phytochemicals that fight DNA damaging reactive oxygen species (ROS) and micronutrients like vitamins and minerals.

Grains will contain vitamins, usually B vitamins (some E), but otherwise are carbohydrates. Therefore, with the same volume of grains as local farm-raised vegetables, you do not obtain the same value for your calories. Nutrients are vital for cellular processes, including reducing inflammation, cancer prevention, insulin regulation, etc.

Being low in nutrients and high in calories contributes to our obesity epidemic. People have excess stored energy in fat but are malnourished due to low levels of vitamins and minerals necessary for health and wellbeing.

The effect on insulin

Devoid of nutrients, whole grains are, in essence, a carbohydrate. Carbohydrates will break down into parts, often in the form of glucose.

When glucose levels elevate, your body makes insulin via the pancreas to drive these levels down in the bloodstream. Over time, with high glucose levels in the bloodstream, your body will become accustomed to the signal to make insulin but resistant to the effect of insulin, therefore leading to excess storage of glucose in the form of the more space-efficient fat molecules: the result, spare tires, pot bellies, and obesity.

Each carbohydrate has a set point by which it will lead to spikes in glucose. Therefore insulin is termed the glycemic index. The highest glycemic food is sugar, with a 100. The lowest is water which is zero. If you evaluate the glycemic index of whole grains, most bread products that are processed have a score of 100, equivalent to sugar. If you make these bread products whole grain, it only drives the glycemic index down to the ’70s.

These numbers, as opposed to most vegetables (excluding corn and white potato) in the 10-20 range.

With such large spikes in blood glucose levels, insulin resistance remains an issue for people trying to improve metabolic diseases or weight loss with these “healthy” whole grains.

Grains Leads to Less Other Foods

Another issue arises when you eat grains, and that is a portion of other vital macronutrients and foodstuffs. Firstly, instead of eating nutrients, fiber, and dense phytochemical carbohydrates in vegetables, people fill up on grains. See above regarding our discussion of nutrient depletion.

Also, when you eat grains, you tend NOT to consume enough healthy fats and protein. In many cultures such as the “blue zones,” or cultures with high percentages of centenarians, people ascribe to a diet high in monounsaturated and polyunsaturated fats, as well as omega-3 fatty acids. Healthy fats are anti-inflammatory, assisting with numerous chronic health conditions like vascular disease, heart disease, autoimmunity, gastrointestinal illness. Fats also serve as a substrate for neurochemicals, neuron (brain cell) architecture, and hormones.

Hormones are vital to weight loss. Men and women alike who aromatize their sex hormones will lack testosterone critical in maintaining lean muscle mass. Muscle mass helps burn fat and maintain a slim physique, as are proteins. Filling up on grains will limit your intake of fat and protein naturally just due to available space in your GI tract and hunger hormone signaling.

Whole Grains Effect Hunger Signaling

Hunger hormones such as ghrelin are also affected less by carbohydrates, straightforward carbohydrates. The result of these factors will leave your hungry or not satiated, therefore going back for more simple carbohydrate, and consuming more calories, perpetuating weight gain.

An additional point regarding the influence of whole grains on your wellness is that of the impact on the gut. I am confident that most of you know about the concept of gluten sensitivity. Unfortunately, many people believe gluten sensitivity to be a way of seeking attention, but I can tell you, as a Gastroenterologist, this is not the case.

Not only does celiac sprue a disease in which people cannot break down gluten (a protein found in wheat, rye, and barley), but non-celiac gluten sensitivity is gaining the attention of the medical community. In the case of these people, they interact with gluten very similarly to those with celiac disease.

Therefore, gluten can lead to gas, bloating, diarrhea, abdominal pain, nausea, or vomiting within the gut. It can also lead to symptoms outside of the gut: joint pain, brain fog, fatigue, psychological disease. The gluten molecule causes such symptoms by be recognized as foreign by your body and subsequent immune reaction. Ingestion of gluten can also cause leaky gut syndrome (poking holes in the protective barrier of the gut) and may shift your gut microbiome to carbohydrate-loving, harmful organisms, termed dysbiosis.

The result is inflammation, generation of toxic compounds, and the shift toward pathogenic bacteria will also impact insulin and hormone signaling, discussed above.

Another issue with whole grains is digestive enzyme inhibitors. These are compounds inherent to whole grains that act to inhibit your body’s natural means for digestion. For example, compounds such as amylase trypsin inhibitors (ATI), abundant in wheat-based products, inhibit your digestion. Not being able to digest your food appropriately will interfere with your ability to use the nutrients you receive from whole grains and may lead to undigested products in your gut, which can induce inflammation and shift your microbiome location (termed small intestinal bacterial overgrowth). Undigested food in the gut can also cause fermentation of the carbohydrate, which generates gas.

There are also many added pesticides and chemicals to whole grains that can adversely affect your health.

What is the Alternative to Gluten-Containing Whole Grains

Instead of consuming gluten-containing whole grains, I recommend eating a rich diet in phytochemicals and micronutrients through vegetables. Given the variable glycemic index of vegetables, divide your veggies into non-starchy like lettuces, brassicas (broccoli, cauliflower), radish, etc., and starchy like sweet potato, carrots, and tubers.

The starchy veggies will allow you quickly release fuel in the form of glycogen in your muscles to power your daily activity and workouts. At the same time, non-starchy will give you fiber and nutrient density to fuel your body’s biochemical reactions. Vary the color and stay seasonal and local when able. Keep the ratio of starchy to non-starchy 1:4

If you crave grains or grain-based products, choose oats, non-white rice, amaranth, quinoa, or other gluten-free grains. Staying gluten-free with your grains will help avoid the issues mentioned above of inflammation, dysbiosis, etc. You can replace these gluten-free grains with starchy veggies if needed. However, ensure you have adequate non-starchy veggies to keep your micronutrient content high.

Summary

As humans, we evolved to consume whole grains to ensure high amounts of calories and a stable food source during times of scarcity. Now that our society has sound food sources available, we should shift toward nutrient-dense foods rather than calorie-dense, nutrient-poor whole grains. Whole grains keep us from eating other vital macronutrients like fat and protein. In addition, the gluten content, digestive enzyme inhibitors, and herbicides of most whole grains are detrimental to our health due to inflammation, gut permeability, and changes in our microbiome. Instead, supplant these whole grains for vegetables and nongluten-containing grains.