The US Department of Agriculture is the body ultimately responsible for setting the Dietary Guidelines for Americans. These guidelines have barely changed since their inception in 1977. They encourage carbohydrates, strongly discourage fats, and recommend eating dairy and meats sparingly (it is the department of agriculture, after all). We are told these guidelines are science-based and healthy. They are neither. I have shown how guidelines on saturated fat, fibre, salt, cholesterol and even water are not science-based, and explained why. Given that the guidelines came into force just when Americans started gaining weight, and stayed in force while obesity increased, it is likely that the guidelines are not fighting this epidemic, they are causing it. Authorities deny this and blame you instead. They blame the overweight for eating too many calories and not exercising enough. Telling obese people they eat too much is as useful as telling alcoholics they drink too much.
But, what if eating and inactivity are symptoms of obesity, not causes? In that case, we should not be targeting these symptoms, but rather identifying the cause and targeting that. Lets get an understanding of this by looking at some biology.
Glucose is the building block of carbohydrates. When carbohydrates are eaten, the body swiftly breaks them down to get as much glucose as possible. It is then faced with a choice – to use that glucose for energy right then, or to store it for later. It can be stored as fat, or converted into glycogen by the liver and stored there or in muscle (as an energy source during intense exercise).
The body needs to make this choice quickly because, even though glucose is an important energy source, glucose is also toxic to us. As surprising as that might sound, it is not uncommon – for example the oxygen that we breathe is essential, but oxidation is damaging and we need anti-oxidants to survive. If there is too much glucose around, it can attach itself randomly to proteins and fats and cause them to dysfunction (a process known as glycation).
If the decision is to store the glucose, then the pancreas drives the fat-storage mechanism by releasing insulin that puts the spare glucose into fatty (adipose) tissue. But, insulin doesn’t stop there – it opposes the burning of fat to release that glucose for energy. Insulin locks the glucose away as fat and throws away the key. Under normal circumstances, and so long as there are not too many carbohydrates in the diet, this all works itself out. Once glucose levels in the blood drop too low, other messengers (e.g. glucagon) start to release stored fats that are broken down by the liver to produce ketones – an alternative and efficient energy source. This is the main way fat stores are mined and fat reduced. If there is always glucose around (because we continually eat carbohydrates), then the ketone mechanism doesn’t get triggered, and insulin just keeps storing ingested glucose as fat.
Furthermore, the pancreas normally responds quickly and effectively to lock away the glucose. We then run out of glucose a few hours later. But rather than letting the ketone mechanism deal with it, hunger signals are sent to the brain and the brain directs us to a food source, which will be more carbohydrates if we are following the USDA high-carbohydrate diet. The ultimate regulator is the brain.
In the end it becomes circular and reinforcing. Eat carbohydrates – store fat – get hungry – eat carbohydrates – repeat. Every few hours of every day of your life. It is asking for trouble. Furthermore, since glucose is locked away, energy levels are chronically low. The result is inactivity. With this model, eating and inactivity are symptoms of an excess of carbohydrates in the diet. Obesity is the outcome.
Many diets restrict calories and that can be effective, but the dieter will always be hungry and miserable and ultimately might give in and the diet will fail. We need a way to restrict carbohydrates but not calories. That is, to feel full while still restricting carbohydrates. Enter fat and protein.
Dietary fats are mostly triglycerides – which are molecules of glycerol with 3 fatty acids attached (I’ve explained this in more detail here). On digestion, the body uses the fatty acids for multiple functions and structures in the body (including cellular energy), and converts the glycerol molecule into glucose, which can then be utilised for energy.
Proteins are often associated with fats, as in a marbled steak. Proteins are assemblies of amino acids. Think of amino acids like the letters of the alphabet – there are only 26 letters but they can be arranged in seemingly endless ways to make different words, sentences and blog posts. Similarly, the body arranges amino acids to make, together with fatty acids, virtually everything that we are constructed of – flesh, bone, muscle, organs, cells, blood… everything. There are 20 different amino acids, and just like the fatty acids, some (9 of them) are essential and must be eaten.
When the body digests protein it breaks it down to its amino acids and uses them to build different proteins as required. If there is more protein than it needs, and if the body is low in glucose, it breaks the amino acids themselves down further and uses the carbon, oxygen and hydrogen atoms to make glucose.
Therefore, both fat and protein are a source of glucose and energy. In fact, the glucose that we get from them can be enough for human needs. Although carbohydrates are considered a macronutrient, carbohydrates are not needed for survival. The same cannot be said for either fats or proteins, as there are dietary requirements for essential fatty acids and essential amino acids. If proteins were removed completely from our diet we would last 2-3 months before feeling sick. If fats were removed completely from our diet, we would be hospitalised within a week. If carbohydrates were removed completely from our diet, we could survive and be perfectly well.
All of which makes the USDA guidelines unphysiological and unhealthy. They tell us to eat more of what we don’t need (carbohydrates) and less of what we do (fat/protein).
In the longer term, the carbohydrate merry-go-round is damaging because stress is placed on the pancreas as it continually releases large amounts of insulin. As well, the body habituates to this insulin so that even more must be released. This habituation is known as insulin resistance. If it goes on too long the pancreas fails, which results in death from Type II Diabetes. Again, from this perspective, obesity doesn’t cause diabetes, diabetes causes obesity.
It seems that there is a spectrum of insulin resistance in the population, and this may worsen with age. So, even without diabetes, there will be some people who are more insulin resistant than others and who will therefore put on weight faster than others. It is also why some people put on weight later in life (e.g. in middle age) – after decades of an over-active glucose/insulin cycle, insulin resistance builds up and the weight goes on faster.
If you look at obesity as a symptom of insulin resistance due to an excessive lifelong carbohydrate intake, then the solution to obesity changes. Restrict carbohydrates and make up for any resulting hunger, not by resorting to carbohydrates, but by increasing the fats (animal fats, not ‘vegetable’ oils). This is known as the High-Fat Low-Carb (HFLC) approach, and it is opposite to the USDA’s Low-Fat High-Carb (LFHC) diet.
HFLC diets have received little attention, not because scientists are not interested, but because the USDA, backed, as it is, by government and industry, has effectively silenced different thinking. Scientists exploring different thinking risk losing their funding, which can mean losing their jobs and their careers. This is real. Only a few have withstood the onslaught (usually those with independent funding). But things are changing, the first HFLC conference was held in 2015. If you want to know more about HFLC, go here.
It is not my intention to promote any diet. But this is an interesting hypothesis and worth exploring. It may not explain all the data (for example, sugar consumption has declined since 2000 but obesity continues to rise). Furthermore, unless a diet becomes a lifestyle without triggering homeostatic adjustments it will fail. Nearly all do. But, we are overdue for research into modern biological- and evidence-based approaches to dietary systems. Something we have not had from government authorities for the duration of the obesity epidemic.
For more information, visit my KETO-DIET Page
This post is based on the work of the Noakes Foundation. Professor Tim Noakes came to my attention when I was researching the 8-glasses of water a day rule. He was the driving force for overturning life-threatening advice to drink copiously during endurance running. His adversaries were PepsiCo (gatorade) and Coca-Cola (powerade). It took him 20 years. Now, as a proponent of HFLC, he is on trial by the Health Professions Council of South Africa (he is based in Cape Town and a medical professional, although he does not practice). He is charged with issuing “unconventional advice” in a tweet. Seriously. The trial started mid-2015 and is ongoing. As if science should be on trial. We’ve been there before.Print This Post