It seems like the trend among fitness enthusiasts nowadays is to demonize carbohydrates. If I had to name one dietary myth that has withstood the test of time, it would be the “carbs are bad, BRO!” myth. A few decades ago, food manufacturers would proudly print “contains no fat” on their products’ labels. Fat was deemed the hidden evil. The demonization of carbs started when the “fat is bad” trend was dying. People had caught on the fact that fat doesn’t make you fat. They had finally realized that obesity rates were increasing thanks to a sedentary lifestyle accompanied with high-calorie palatable food. Consequently, food manufactures started looking for a new scapegoat. Since we’re always looking for someone, or rather, something to blame, carbs have been officially declared evil. Supposedly, the currently-despised macronutrient is responsible for making us fat. Unfortunately, this myth doesn’t seem to be disappearing anytime soon.
TL;DR Version
- Carbs don’t make you fat.
- You can effectively lose fat on a high-carbs diet.
- Losing fat is more complex than simply keeping your insulin levels low.
- The human body is capable of making carbs from protein and fatty acids.
- Not everyone can perform well on low-carbs.
Flashback
The common dietary fad a few decades ago was based on avoiding dietary fat. Food producers had successfully brainwashed our population into thinking that eating fat makes them fat. Unsurprisingly, food producers started pumping out low and non-fat products. Food tasted like cardboard and people ate it in hopes of losing weight. Yes, fat is the most energy-dense macronutrient. A gram of fat contains 9 calories. Thus, energy overconsumption is easy when one’s diet is high in dietary fat. Here is the shocking part: despite a significant reduction in energy consumption caused by substantial reduction in consumption of dietary fat, obesity rates increased significantly! What happened? This medical observation lasted from the 1970’s through the 1990’s. People were consuming the least amount of dietary fat for over two decades but, obesity rates continued to rise substantially during the same period! Coincidence? I don’t think so. Researchers concluded that a diet high in fat was not the main cause of obesity and, avoiding dietary fat will not do much to solve the obesity problem. Another study (meta-analysis) observed the same phenomenon in other countries! Why am I discussing dietary fat in this article? Because the same bullshit is happening all over again! Besides ignorance, certain figures want you to believe that something is bad so they can make profit. It has happened in the past and will continue to happen till the end of time. Read along.
Carbs don’t make you fat
I am going to let you in on a little secret. Do you know what causes you to gain weight? A CALORIC SURPLUS! Voila! There you have it. The secret of all secrets. In fact, a caloric surplus doesn’t make you fat. A prolonged caloric surplus will make you fat. If you are eating 1000 calories more than you burn daily, you will gain weight quite fast. And, if you continue to eat at such a large calorie surplus for an EXTENDED period of time, you will put on a significant amount of weight, mostly in the form of fat. There is no such thing as one macronutrient making you fat. A surplus of energy is what causes anyone to gain weight. Sedentary lifestyles and highly palatable foods are the two main contributors to obesity around the globe. Throw in crappy food choices, high stress levels, and inflammation and the effects of those two factors are augmented.
But, carbs blunt lipolysis…
No, carbohydrates, technically, do not block fat breakdown. This is even more true in presence of a caloric deficit – the number one factor of losing weight/fat. Yes, carbs do spike insulin, which is a storage hormone; however, just because you spiked your insulin doesn’t mean you will “gain fat”. First, let’s shed some light on something important; just because a study was conducted on a certain matter doesn’t mean you should jump to conclusion. Very often, a study will have detrimental flaws that should make the reader dismiss the study entirely. If a major flaw is missing, one should look at limitations of the study.
Cherry Picking Studies
When a fitness figure is trying to reinforce an idea, he/she will often attempt to cite some studies to sound authoritative and credible. What usually happens is the person in question hand-picks studies that support his claim disregarding detrimental flaws in the cited studies. Not cool, bro. Let’s look at some examples.
NOTE: Keep in mind that the studies below did not study the effects of different dietary protocols on young health strength athletes.
Crappy studies
Example #1 – An often cited study among the low-carbs crowd is the Foster GD, et al. ( 2003) study. The study at hand supposedly proved that a low-carbohydrates diet is superior to a low-fat diet in losing weight. But, there is one major flaw in the method used! 63 individuals were randomly assigned to either a low-carbs or a low-fat group. The low-carbs group ate ad-libitum (at will). Meaning, they did not follow a calorie-restricted diet. However, the low-fat group followed a calorie-restricted diet (1500kcal)! In other words, the results of those who ate as much as they wanted were compared to those who were energy-restricted! The main flaw here is exactly in the number one requirement of weight gain/loss: energy intake. Undoubtedly, the two groups had severely different energy intakes. Thus, the results of both groups should not be compared concretely. Ironically, the researchers observed that individuals who followed a low-carbs diet lost significantly more weight by the 3 and 6 months’ marks but, the results were not even statistically significant at the 12-months mark.
Example #2- Samaha FF, et al. (2003) compared the effects of a low-carbs diet vs. a low-fat diet on weight loss. 132 individuals with severe obesity were randomized to either group. The subjects had either metabolic syndrome or type II diabetes. I won’t even continue to explain the study at this point because the sample is not relevant to most of the population. The sample should’ve included obese healthy individuals. The sample should be even different when addressing the strength training population.
Example #3- Volek JS, et al. (2004) also compared the effects of a low-carbs ketogenic diet vs. a low-fat diet on fat loss. 15 healthy, overweight/obese men and 13 premenopausal women were randomized and assigned to either group. The researchers observed that the low-carbs group lost more fat than the low-fat group. Both diets were energy-restricted (which is much better than the studies above). However, the researchers noted that men who were put on a low-carbs diet lost more fat, and more visceral fat than women who followed the same dietary protocol! Moreover, women who ate low carbs did not lose significantly more weight than women who followed the low-fat diet. The researchers concluded that a low-carbs diet is superior for fat loss. Not so fast! Three problems with the study at hand are: 1) The number of male subjects exceeded the number of female subjects. 2) Not all female subjects lost more fat on the ketogenic diet. 3) Subjects had different activity levels! Some were exercising while others were sedentary. What could be concluded from this study? Men and women should follow different dietary approaches. In fact, women perform better on a high fat diet than men due to different hormonal environments.
There are many more studies whose conclusions shouldn’t be generalized. By now, you should see my point. It’s vital to read and analyze studies meticulously. Not every study should be thrown around as the be-all and end-all of studies.
Opposing studies
Example #1 – Meckling KA, et al. (2004) compared the effects of a low-carbs diet vs. a low-fat diet on body composition. 40 overweight subjects were assigned to either group. Subjects included 10 males and 30 females (Remember, men and women shouldn’t follow the same dietary protocols). Both diets were energy-restricted, however, the LC (low-carbs) group were in a larger caloric deficit (3195 kj/day) vs. the LF group (2540 kj/day). Results? The LC group lost 0.2 kg more than the LF group, which could be simply attributed to the higher caloric deficit. Interestingly, the LF group retained more lean body mass! Meaning, the LC group lost more lean mass.
Example #2- Brinkworth GD, et al. (2009) compared the effect of the same dietary approached in the studies above on weight loss. 118 individuals with abdominal obesity followed a calorie-restricted diet for 1 year. They were assigned to either a low-carbs group or a low-fat group. The LC group lost a total of 32 lbs. while the LF group lost a total of 25.3 lbs. Results were not statistically significant.
Thus, from the studies above (and many others), we can conclude that the number one element of weight loss is a calorie-deficit. Macronutrients do play a role in weight loss but, not to the extent that many people think. An energy-deficit is what matters most. Let’s continue.
Carbs, Insulin, and Lipolysis
Insulin is one of the most demonized hormones ever. Mainstream media has done a great job at convincing people that insulin makes you fat and unhealthy. To bodybuilders, insulin is known as the most anabolic hormone in the human body. The truth lies somewhere in between. Insulin is a storage hormone. The body secretes insulin in response to food consumption. As many of you know already, carbs do spike insulin. But, so does protein. Combining protein and cars will cause even more insulin to be secreted. Insulin is responsible for storing nutrients from food. It does so by pushing nutrients into cells; however, it pushes nutrients into both muscle cells and fat cells. Thus, it is misleading to say that insulin just stores fat. The amount of nutrients and energy stored as muscle or fat depends on several factors, such as; the amount of nutrients consumed at a time, number of calories consumed at a time, insulin sensitivity, when the nutrients are consumed (nutrient timing), and whether the person is training or not. If a person is sedentary, majority of nutrients will be stored as fat. If a person is insulin resistant and thus suffers from poor nutrient partitioning, most nutrient will be stored as fat. That said, it is safe to say that we all spike our insulin levels even when eating less energy than we expend (calorie deficit). So, how do we still manage to lose fat despite spiking insulin?
The answer is; we store and lose fat throughout the day! As I have mentioned before, a favorable change in body composition is merely a product of maximizing favorable outcomes and minimizing unfavorable outcomes. It is the net result after a period of time that matters, not what happens on a daily basis.
At any given moment, our bodies are either storing fat or burning fat. This, of course, depends on food intake. If the amount of fat burnt over a period of time is much greater than the amount of fat stored, you will have “lost fat” and improved your body composition. Thus, it is the net result.
The interesting thing is that anti-carb people often mention insulin secretion when defending their stance. And, quite frankly, they are somewhat correct. But, protein is also insulinogenic yet, no one says that protein prevents fat breakdown. Well, as usual, the human body is more complex than we think. Carbs do spike insulin but, losing fat is still possible. To understand this clearly, two terms must be identified.
(I highly recommend every carb lover or hater to read this article by Lyle McDonald)
Post-prandial phase: Refers to the time after eating a meal
Post-absorptive stage: The stage between two post-prandial phases.
During the post-prandial phase, food is being digested and nutrients are being released into the bloodstream. In response, the body secretes multiple hormones, including insulin. This puts the body in anabolic state (storing nutrients and energy).
During post-absorptive stages, the body has finished digesting and storing all nutrients and has nothing to do. As a result, the body transitions into a catabolic state (releasing stored nutrients).
Thus, the body switches between those two phases throughout the day. Sometimes, it stores nutrients and energy and, other times, it is releasing stored nutrients and energy. The larger a meal is, the more time the body will spend in an anabolic state (post-prandial) and, vice versa. So, when one starts dieting and starts consuming less energy than they expend, they ultimately spend more time in a catabolic state (post-absorptive phase) than they spend in an anabolic state. In other words, given that they are training properly and dieting intelligently, they will be burning more fat than they store. This will ultimately result in significant fat loss and a leaner body.
Myth: Insulin is only secreted post carbs consumption.
Fact: Insulin is secreted in response to FOOD consumption, not just carbs.
Another reason why eating low carbs is not a prerequisite of losing fat/weight is the fact that carbohydrates are not essential to humans’ survival. The human body is capable of producing carbs from protein and fats and using them as energy (gluconeogenesis). So, even if you intentionally deprive yourself of carbs, your body will still manufacture them using dietary fat (or stored fatty acids) and protein.
Why do people lose weight on a low-carbs diet?
Simple, because they intentionally or unintentionally create a caloric deficit. The prevalence of highly-palatable foods plays a major role in people gaining weight. An average-sized doughnut has 400 calories. Many will be quick to conclude that doughnuts are fattening because they have tons of carbs but, they will disregard the fact that consuming 400 calories through one doughnut is easy. Moreover, an average-sized doughnut will not contribute much to satiety, making them incredibly easy to overeat. Thus, a person will most likely consume several doughnuts to feel full. This will consequently make the calories rack up faster than one might think.
Take Home Message
Eliminating carbs from your diet is not essential for fat loss. As usual, an energy deficit is the sole requirement of weight/fat loss. When constructing an intelligent nutrition plan, one must consider the following elements:
Individual tolerance – Even though you can still lose fat effectively on a high carb diet, you should still take into account your personal tolerance. Some people tolerate carbs very well. Putting those individuals on a low-carbs diet is counterproductive and unsustainable. On the other hand, some individuals do not tolerate carbs well and may be better off following a low-carbs diet. As usual, genetics play a major role.
Personal preference – Some people cannot live without carbs while others can. Personal preference plays a huge role in diet adherence which is a major component of a successful cutting/dieting phase.
Performance – Undoubtedly, carbs can improve performance. Following a low-carbs diet could severely affect one’s performance. This is important if you are an endurance athlete.
References
Frederick F. Samaha, M. N. (2003, May 22). A Low-Carbohydrate as Compared with a Low-Fat Diet in Severe Obesity. Retrieved from The New England Journal of Medicine: http://www.nejm.org/doi/full/10.1056/NEJMoa022637
Gary D. Foster, P. H. (2003, May 22). A Randomized Trial of a Low-Carbohydrate Diet for Obesity. Retrieved from The New England Journal of Medicine: http://www.nejm.org/doi/full/10.1056/NEJMoa022207
Grant D Brinkworth, M. N. (2009, July). Long-term effects of a very-low-carbohydrate weight loss diet compared with an isocaloric low-fat diet after 12 mo. Retrieved from The American Journal of Clinical Nutrition: http://ajcn.nutrition.org/content/90/1/23.long
JS Volek, c. a. (2004, Nov 8). Comparison of energy-restricted very low-carbohydrate and low-fat diets on weight loss and body composition in overweight men and women. Retrieved from Nutrition & Metabolism: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC538279/
Kelly A. Meckling, C. O. (2004, June 1). Comparison of a Low-Fat Diet to a Low-Carbohydrate Diet on Weight Loss, Body Composition, and Risk Factors for Diabetes and Cardiovascular Disease in Free-Living, Overweight Men and Women . Retrieved from The Journal of Clinical Endocrinology & Metabolism: https://academic.oup.com/jcem/article-lookup/doi/10.1210/jc.2003-031606
WC, W. (1998, Mar). Is dietary fat a major determinant of body fat? Retrieved from The American Journal of Clinical Nutrition: https://www.ncbi.nlm.nih.gov/pubmed/9497170
WC, W. (2002, May). Dietary fat plays a major role in obesity: no. Retrieved from Obesity Reviews: https://www.ncbi.nlm.nih.gov/pubmed/12120421
