Mark Twain was the master of words and here is his take on health: “The only way to keep your health is to eat what you don’t want, drink what you don’t like, and do what you’d rather not.” Seriously though, it does not have to be that bad.
Before we embark on this educational journey I would like to highlight two types of variables (hurdles) we have to deal with: Systemic and idiosyncratic variables.
Systemic variables such as genetics, pollution levels, food quality and availability of various types of food, weather, etc., are not in our immediate control. I am not addressing these issues here but they are known to have a huge impact on our abilities and overall well-being. This is especially true in situations where highest level of performance is expected. For example, we can see the impact of these systemic variables in sports: Pele in soccer, Michael Jordan in Basketball, Serena Williams and Federer in Tennis, Wayne Gretzky in Hockey, Takeru Kobayashi in Competitive Eating, Usain Bolt in Sprint, and a few others in other sports. I don’t want to take their passion and hard work away and say that these people are successful just because of their genetics. But it is hard to argue that Wayne Gretzky practiced harder than Mario Lemieux or Jaromir Jagr.
Takeru Kobayashi weighs about 130 lbs (59 kg) but he can down 106 tacos in 10 minutes. He also ate 62 slices of pizza (over 15 full pizzas) in 10 minutes in 2014 and the guy is skinny. I can make an even more compelling argument on the importance of systemic variables using Usain Bolt as an example in the sport of 100 meter sprints.
100 meter sprint is an extremely competitive sport. We have both official and unofficial world records for 100 meter races going all the way back to 1891. The world record started out at around 10.8 seconds in 1891 and Jim Hines broke the 10 second barrier in 1968. But then the 100 meter record plateaued out at around 9.8 seconds (+/- .05 seconds) in 90s for almost two decades. World class sprinters kept improving on the record by a meager 0.01 to 0.02 second per attempt during this time. These sprinters had access to best training equipment, coaches, diet and everything else you can imagine. But then here comes a tall young lad named Usain Bolt and breaks the previous record by a whopping 0.16 second. Jim Hines ran a 9.95 second race in 1968 and the 2008 record was 9.74 seconds. It took almost 40 years to lower the record by 0.21 second (~0.005 second improvement per year.) Bolt broke the previous record by a whopping 0.16 second in one year! He famously revealed his pre-race meal secret on David Letterman’s show: McD’s chicken nuggets.
Bolt is an unbelievable talent and set the world record despite his diet. My point is genetics and other systemic variables do play a major role in one’s ability to achieve one’s goals. We all have our systemic limitations but our goal should be to find an optimal lifestyle that improves our Quality of Life (QoL.)
Idiosyncratic variables are the ones we can control such as diet, exercise, good habits, stress, etc. But please internalize this: We are still trying to solve a 10 variable problem by optimizing just 4 variables. Exercise, stress management, and good habits (maintaining a good hygiene, staying focused, not smoking, not drinking, not doing drugs, etc.) are obvious and I will only focus on diet here.
Before we get into all those nitty gritty details, let me caution you that the whole nutrition business is a trap. If you get sucked into nutrition management you can piss away your hard earned money, literally. Most of the pills and vitamin supplements are not a good source of nutrition. Once you get into this you will find out that you are always low on something; an enzyme, some form of protein, a weird vitamin, or some hot hormone. It never ends. Also, ignore all those outlandish marketing campaigns: “pomegranates – Gods food!” or “Turmeric is divine” or “Green matcha tea brewed at 50 degrees is what Gods drink.” If you ask me, one should never take advice from a person who makes frequent visits to God’s abode. How else would this person know what Gods eat and drink? Also, if that is what we get to eat for eternity, maybe we should try something else while we are here on this 3rd rock from the Sun.
Let me get on my soapbox now. Homo sapiens are a well adopted bunch. We are generalists when it comes to our food but some of our distant relatives (Pandas, Gorillas, Anteaters (look at Michael Jordan’s tongue)) have specialist (restrictive) diets. We can survive/thrive on plants, fruits, bugs, nuts, fish, milk, and meat. This ability (among others) turned out to be a huge advantage for our species and helped us become supreme commanders of the universe. You don’t believe me? Just look at what happened to Pandas in the wild. They specialized in eating bamboos, exclusively bamboos mind you. But humans had other plans and in a matter of few decades we almost wiped Giant Pandas out of existence and put them on the endangered list. Fortunately for Pandas they are cute and cuddly. Thanks to their good looks and a few good people’s intervention we upgraded Giant Panda’s status to “Vulnerable list” from “Endangered list” last year.
Our bodies are complex biochemical reactors. All the complex organic, biological, and electrochemical reactions that take place in our bodies are not fully understood yet. Research on enzymes, hormones and various proteins present in our bodies is still ongoing. So, why not look at a much simpler reactor, the internal combustion engine (ICE), for example, to understand the complexity of our problem. Some IC engines are tuned to go really fast, others to haul large loads and some others to generate a lot of thrust. And these engines consume different types of fuels to perform their respective tasks. How come then when it comes to our most complex biochemical reactors all we need is a fuel mix of 60% carbohydrates, 20% proteins, and 20% fat? This does not make sense. We have populations getting almost 80% of their daily calorie intake from fats and we also have populations getting the same percentage of calories but from carbohydrates. Each population sub-group has its own longevity curve. We can always find opposing views and data points in every sub-group to justify our own shtick.
To complicate things further, not everyone can digest and extract the same amount of nutrition from the same food. For example, can we be sure that everyone can extract 40 calories by consuming 100 grams of carrots? A lot of us can’t digest a lot of foods. Not all of us can produce appropriate amounts of enzymes needed to digest all these various types of foods for various reasons. Some folks are good at extracting better nutrition from the same quality and quantity of food than others. You hear these stories from time to time about people living on just celery and ginger (ok may be with some lemon zest and non-fat mayonnaise dip – eggless one!) and doing well. Don’t confuse extreme cases for averages. And here we are trying to solve cardiovascular disease with fruits and nuts.
In summary, we used to eat all kinds of stuff and used to be masters at managing feasts and fasts. Our bodies evolved storing fat during feasts and burning fat during fasts. We moved from eating diversified and complex foods with frequent feast and fast cycles to highly standardized, simplified and processed foods with predetermined feeding cycles.
You may be thinking, enough already, I get it. Well, I am belaboring this point for two reasons:
- Most of the studies and research papers I came across made one point very clear and here it is: Our digestive systems are very different and no single diet works for all.
- Seriously, the title makes it abundantly clear that complexity is the answer. How can I give you a simple explanation?
So, whatever you read here may or may not work for you. It is not because the information is wrong; it is because you are special!
If you are not the probing kind and just want to know the answer for the diet question, here it is:
- Eliminate white/brown sugar from your diet completely. Only source of sugar in your diet should be from natural foods such as fruits and veggies. But remember in some cases you may have to reduce even those to see any results.
- Increase your fat intake as percent of your total calories within reason.
- Experiment with the amount and type of carbohydrates you consume (should be mostly from vegetables and fruits) and determine what is optimal for you. For example, some people respond well by just cutting sugars out but others may have to bring their total carbohydrate intake down to 15% – 20% of total calories.
- Of course, consult your physician before getting onto any special diet especially if you have any hormonal or other health issues. Give it at least 6 months before you question the diet.
Ok, for the rest of us curious critters, here are the details. While reviewing the fat consumption versus heart disease controversy in Part Unum, I realized that the spread in fat consumption among various groups within the developed world is not that dramatic (~20% vs 40%.) However, Dr. John Yudkin made a compelling argument against sugar in his book, “Pure, White and Deadly”. I looked around for sugar consumption data online and here are a few charts I found to support Dr. Yudkin’s argument.
Here is a chart showing sugar consumption in the US since 1820s (source: Data from Dr. Stephan Guyenet’s blog.) Please note that this data set only includes sugar consumption from direct sources such as, sugar cane, beet, High Fructose Corn Syrup, Maple syrup, other sweeteners, etc. This data set does not include sugars from consumption of fruits and vegetables.
Apparently Americans were consuming about 8 grams of sugar per day per person (that is about 2 teaspoons) in early 1800s but that number shot up to 100 grams per day per person (31 teaspoons) by 1920. Current estimate is around 125 grams per day per person or about 100 pounds (~46 Kg) of sugar a year. Sugar consumption jumped by a whopping 15X in 200 years in the US. I doubt saturated fat consumption changed that much during the same period.
How about we go back another 100 years? I found exactly that in Dr. Richard J Johnson’s article, “Potential role of sugar (fructose) in the epidemic of hypertension, obesity and the metabolic syndrome, diabetes, kidney disease, and cardiovascular disease” published in the 2007 The American Journal of Clinical Nutrition medical journal (it is peer reviewed.) Here is the chart with the data.
UK’s sugar consumption since 1700 is shown in the above chart. UK’s per capita sugar consumption in early 1700s was around 1.8 kg per person per year (~ 5 grams/day/person or 1.2 teaspoons) and it jumped to about 8 kg per person per year (22 grams/day/person, 5.5 teaspoons) in 1800s. Then per capita sugar consumption sky rocketed to 55 kg/year/person (150 grams/day/person or 38 teaspoons) by 1970s. That is more than 30X increase in sugar consumption in 300 years. They also show consumption of sugar in the US from 1970 to mid-2000s and overlay obesity prevalence in the US since early 1900s. The US obesity prevalence shot up from less than 10% in early 1900s to over 40% in early 2000s.
Scientists believe that it takes between 1,000 (30,000 years) and 10,000 (300,000 years) generations before any species can adapt to a major change. We have been eating grains in large quantities for about 10,000 years and some of us still have allergies. And now we have increased our sugar consumption by over 30X in 300 years.
Can you think of any chemical reactor that can handle such a big change in its feedstock without major engineering redesign? Can you imagine what kind of stress we are putting on our pancreas? If you were to run a correlation between heart disease and another variable, would you consider running fat or sugar as a variable first? Of course, sugar alone probably can’t explain all the problems in our society but can be a starting point for a debate.
Ok, can we correlate this jump in sugar consumption to any other disease? How about diabetes? Here is a chart from Center for Disease Control (CDC) on percentage of US population with diagnosed diabetes.
Diabetes jumped from about 1% of the US population in 1958 to 7% of the total US population in 2014.
Here is CDC’s data on prevalence of obesity among adults between the ages of 18 and 29 in the USA.
The low fat diet fad started in the mid to late 1980s in the US and unfortunately fat was replaced by sugary foods labeled as non-fat. We can see a clear correlation between change in diet and obesity.
Obviously I can’t establish causation but there seems to be a correlation between sugar consumption and diabetes/coronary disease/obesity. Dr. John Yudkin tried to establish causation in his book mentioned earlier. He looked at research studies in Israel, UK and the US among certain groups and clearly identified sugar as the primary culprit. Apparently recent immigrants from Yemen to Israel in 1970s had very little coronary disease, though the disease was common (similar to native Israelis) among Yemenis who had immigrated 20+ years ago. Recent immigrant Yemenis also fared well in diabetes tests with only 0.06% suffering from diabetes versus 2.9% of the earlier Yemeni immigrants. A.M. Cohen and his colleagues from Jerusalem (scientists of the study) observed that the only noticeable difference between these two Yemenis groups is the amount of sugar consumed in their diets. Yemeni diet tends to be rich in fat and very low in sugar. Earlier Yemeni immigrants adapted to local dietary habits and increased their sugar consumption significantly.
Dr. Yudkin observed similar trends among Asian immigrants in the UK and the US. Diabetes/coronary disease is almost 3 to 4X more prevalent among Asian immigrants in the UK and the US than among their European peers. Again amount of sugar in the diet was the primary difference.
I hope I made some compelling arguments against consuming simple carbohydrates, especially sugar. But please note that I do not subscribe to the idea of cutting carbohydrates completely. Let me explain why I think a balanced nutrition, especially emphasis on missing nutrients, is the key to long-term health.
Carl Sprengel came up with it and Justus von Liebig popularized a law in agricultural science called Law of the Minimum in the 19th century and it states that growth and yield of a plant is not controlled by all the resources available to it but by the scarcest resource. This law is now popularly known as Liebig’s Law of the Minimum and agricultural scientists use a barrel called Liebig’s barrel to explain the law as shown below.
I think we can apply Liebig’s barrel philosophy to human nutrition as well. Please think about this for a moment. Let us say a person is low on Vitamin D and feels tired all the time. Does it help if the person consumes more carbohydrates thinking lack of calories is the cause of overall weakness? Dr. Yudkin mentioned in his book, “Pure, White and Deadly” that it took almost 20 years for scientists to figure out the treatment for pernicious anemia. Vitamin B12! Apparently raw or lightly cooked liver seemed to work for the patients and scientists finally linked it to vitamin B12. It is not that easy to figure these things out.
We are generalist feeders. As long as we don’t have major dietary restrictions we should be able to get all the nutrition we need from natural foods. That is how we evolved. By the way, restrictive diets are not just limited to some humans. Our favorite species Pandas do that. Apparently Pandas evolved from carnivores but somewhere along the way they chose to eat bamboo. Pandas can digest meat but they prefer bamboo shoots. Some scientists claim that Pandas absorb less than 20% of the energy content of bamboo shoots. A carnivore typically absorbs between 60% and 90% of the energy it consumes. Pandas’ food choice is very inefficient and yet Pandas thrive on bamboo. So, it is possible to survive on restricted diets but one must watch out for missing nutrients.
Let us talk about metabolism and dig a little deeper into how we absorb our macronutrients. We briefly discussed this in Part Unum but let us take a closer look at metabolism of fats, proteins and carbohydrates.
Almost 90% of dietary fats are made up of Triglycerides (TAGs.) That is right! We eat TAGs, digest them and convert them back to TAGs. Various types of enzymes play a key role in the digestion and absorption of fat and the digestion process starts with lingual lipase (an enzyme produced in our saliva) in the mouth. Think of this step as more of preparation than actual digestion. But chewing is very important because large pieces of fat are very hard to digest in our intestines. Chewed up fat pieces then move to stomach where gastric lipase (secreted by gastric cells) joins the party and all the contents mix well with strong acids (Hydrochloric acid). Then pancreas sends pancreatic lipase to help digest fat and the whole stuff moves into duodenum (part of small intestine.) Remember fat is not water soluble and most of our body is hydrophilic (water loving). Fat tries to cling together in water like a blob in the intestine if something is not done. To help break apart the fat blobs, liver sends bile salts (manufactured from cholesterol and stored in gallbladder) into duodenum. Once bile acids break apart fat blobs, pancreatic lipase does its thing and breaks apart fat in the small intestine. Lipase breaks each TGA into mono glyceride and two fatty acids. The broken down monoglycerides and fatty acids permeate through intestine wall and go through an organelle called smooth endoplasmic reticulum (smooth ER) where they get put back into TAGs. Yep, we spend all this time breaking apart TAGs and finally put them back together again. It is not done yet. Then these TAGs go into another organelle called Golgi apparatus. Our buddy Golgi packages TAGs, some cholesterol, some vitamin D and a few other things into a globule called Chylomicron, a lipoprotein vessel (we discussed about Chylomicron in Part Duo and now we know how it is made) and exports it into our lymphatic system (this process is called exocytosis.) Chylomicrons carrying all the nutrients we absorbed from the fat finally enter the bloodstream through the lymphatic system. Our cells absorb some of the TAGs from Chylomicrons but remember glucose is the preferred fuel. So, the excess TAGs from Chylomicrons are stored in our adipose (fat) tissue and our body extracts stored TAGs from the fat tissue when the need arises.
So, what is a protein? Proteins are long chain amino acids. That is right. We are dealing with all kinds of acids here. Fats are carboxylic acids and proteins are long chains of amino acids. If you really want to know the difference between fats and proteins, here it is: Fats have a –COOH (carboxylic group) at the end of the chain. Amino acids have a carboxylic group on one end and an –NH2 group on the other end. Proteins are water soluble.
After protein is chewed up in our mouth and enters the stomach it mixes with pepsin, an enzyme that helps digest the protein and breaks it into large polypeptides. By the way, the hydrochloric acid in our stomach plays an important role in the formation of pepsin from pepsinogen. Popping/drinking anti acid pills/stuff is not very good for digestion. These polypeptides then move to smaller intestine where some more enzymes secreted by pancreas break down the large polypeptides into small polypeptides or di or tri peptides. More enzymes get into action and break down the small and di and tri peptides into amino acids. Amino acids are hydrophilic and they mix with blood easily and go directly to our liver. Once all the needs of our muscle cells and other cells are met, excess amino acids are converted into glucose and eventually into glycogen for future use. Of course, consuming too much protein can be an issue as one of the byproducts from the metabolism of amino acids in the liver is urea. Liver sends urea to the kidneys for waste disposal and there urea gets flushed out in urine.
We already talked about carb metabolism but here are some additional details. Carbs are starches, sugars, and fibers. Carbohydrate digestion starts in the mouth with salivary amylase. Remember carbohydrates are basically polymers of monosaccharides. Partially digested carbs with salivary amylase reach stomach where the contents get mixed well. Note that digestion of carbs stops in the stomach as the salivary amylase gets deactivated in the acidic environment. Interesting isn’t it? Proteins need the acid and carbs don’t. So, it is very important to chew carbohydrates before swallowing. Partially digested carbohydrates from stomach move to small intestine where they mix with pancreatic amylase and get further digested. Various types of other enzymes such as maltase, lactase, sucrase, etc., hydrolyze various types of polysaccharides into glucose molecules. Note that not all starches such as resistant starch, fiber, etc., get digested in the intestine. Resistant starch and fiber mix reaches colon where the mix gets fermented in the presence of gut bacteria and small fatty acids are extracted out of the fermented mix. The undigested resistant starch and fiber get excreted by the body.
The glucose produced in the intestine gets into the bloodstream and goes directly to the liver. Remember, as soon as glucose hits the bloodstream, insulin is released by the beta cells of the pancreas. We already discussed how insulin helps our body cells absorb glucose in Part Unum. Excess glucose gets converted into glycogen and liver can only store so much glycogen. So, all the leftover glucose gets converted into fat and stored in the adipose tissue. Here is the bad part: The more fat we generate from eating all those simple carbs, the more adipose cells are created to store them. This is probably a good time to introduce the two types of fats we carry around: Subcutaneous fat and visceral fat. Subcutaneous fat resides under the skin. This is the first layer of fat that we gain when we go from super fit to fit. Men tend to store most of it around abdomen area and women tend to store it below the waist.
Subcutaneous fat is not bad and actually good for most people. But as we start packing on more and more of it, we eventually run out of space for fat under the skin. That’s when we start packing fat in our abdominal cavity around various internal organs. This fat is called visceral fat and it is really bad. Only saving grace is that it is easy to burn off the visceral fat. All we have to do is follow proper diet and exercise. But it is very hard to burn subcutaneous fat. That is the reason why getting a six-pack is not that easy.
I would like to digress and add a couple of sentences about alcohol metabolism. Unlike all the other foods, only 10% of alcohol gets metabolized in the gut. Another 10% goes to the brain and that’s why we feel the buzz but the remaining 80% alcohol goes directly to the liver, where it gets turned into fat. Excess alcohol consumption is deadly. Also, did you notice the similarity between fructose and alcohol metabolism. Both of them screw up the liver if consumed in large quantities.
Ok, there you have it. Probably more than what you wanted to know but that is how eating too many carbs makes us fat. That’s why high carb diets, especially high sugar diets, put tremendous amount of stress on a number of our body parts (liver, pancreas, etc.)
Excess simple carbohydrate consumption could make us diabetic. When we create these major insulin spikes by consuming large quantities of sugar, we put a lot of stress on pancreas to secrete more insulin. Since simple carbs get digested relatively quickly, insulin levels also drop quickly from a very high level. When insulin level falls, liver releases glucose from the stored glycogen reserves. Important point to note here is that liver does not know anything about blood glucose level. It only acts based on the insulin level. For example, some people’s insulin receptors may stop functioning properly (type-2 diabetes) for various reasons. That means they can’t absorb glucose efficiently. So, blood glucose level stays high and pancreas produces even more insulin. Liver sees all this excess insulin and stops burning fat and starts storing it. A vicious cycle! Type-1 diabetes is different in that its patients can’t produce any insulin at all and that is the reason why they need medical intervention to control their blood glucose levels. Diabetes could lead to heart disease if proper care is not taken as that is a major source of inflammation.
Key point to note from all of this discussion is that a number of things could mess up our digestive system and that could affect our ability to absorb nutrients. So, one must take utmost care to manage proper digestion. Instead of popping antacid like Mentos or taking some random digestion pills, we should try and figure out the root cause of the problem. We should not mess around with our gastric juices and enzyme production.
So, what does it all mean? Here are a few key takeaways:
- Don’t follow a diet blindly. No two humans are the same.
- Figure out how your body metabolizes various foods you consume and choose the foods that meet your palate and nutrient needs.
- Trial and error is the best way to figure out each individual’s optimal carbohydrate, protein and fat mix.
- Avoid processed foods as much as possible.
- If possible completely eliminate direct consumption of sugar.
- It is ok to eat butter and fats. They are not as bad as marketing machines make them out to be.
- Try to follow latest developments in nutrition research.
- Pay attention to skeptics and critics of conventional views. Health is all we got. Let us not screw it up.
There you have it. There is no simple answer. It is complex. Deep thought back to thinking deep thoughts!