Low-carbohydrate dieting and ketogenic dieting (when carbs are sub ~30-50g) are mega-popular dietary options with seemingly endless anecdotal backing. It isn’t uncommon to find weight loss success stories where hundreds of pounds are lost after removing carbohydrates from the diet.
When consumed in a balanced fashion, low-carb diets are excellent in weight management programs due their ability to downregulate appetite. Most individuals will claim they are not as hungry when eating low-carb.
Anecdotal benefits of eating low-carb also include:
-Heightened mental clarity
-Improved energy levels
-Clear and glowing skin
As a holistic nutrition consultant who is passionate about long term wellness, my concerns lie mostly with how one decides to execute this eating strategy.
While I do not think there is anything inherently wrong with eating a balanced low-carb diet, we still need more research to assess this strategy’s longevity.
How does eating a low-carb diet impact health over the long term?
Does one need to maintain a low-carb diet structure to keep their weight loss results?
Does this strategy pose stress or extra demand on the biliary system? – How can we address this on a larger scale as this diet style gains even more popularity?
While we wait for future studies to evaluate these concerns, let’s examine some of the available data to review commonly overlooked considerations with low-carb dieting.
Energy Balance is Still Relevant
While some members in the low-carb domain might have you believe it is impossible to gain weight on a low-carb diet, this is hardly the truth.
In reality, the total number of calories one consumes daily will always have the most significant bearing on their weight. At this point in our evolution, it would be foolish to reject science outright and believe that we can eat in a limitless fashion without consequences.
The primary reason low-carb dieting works so well is that individuals are just not hungry and tend to consume less without much thought. Meals with high-fat content give a naturally full feeling that overweight individuals are not used to experiencing. Obese individuals commonly experience a conditional dysfunction in leptin/ghrelin ratios, which account for their inability to recognize satiety.
The potential to gain weight or see unremarkable weight loss still exists within a low-carb framework. Diligence must be applied towards total consumption to produce the desired losses in body fat mass.
Confusing Low-Carb with High-Fat
A common confusion when exploring a low-carb eating strategy is to equate it with high-fat eating. While slightly more fat is necessary for this framework, an excess of fat is not always required.
Here are two ways to look at low-carb eating:
The LCHF diet on the left is an example of a carbohydrate-deficient meal plan with an abundance of fat coming from saturated sources. LCHF is the most commonly recognized application of low-carb eating.
The Modified Low-carb Approach has more carbohydrates (coming from mostly non-starchy sources), a balanced fat profile, lean protein options, and more significant contributions of minerals, phytonutrients, and fiber.
Both are considered low-carb.
The execution of low-carb diets can be adjusted to suit the individual’s unique metabolic needs and health status.
Ignoring Effects on Cholesterol
The storage form of fatty acids in the blood called triglycerides, and transporters of cholesterol called VLDL, HDL, and LDL, are considered the primary clinical indicators to assess the health of the cardiovascular system.
Our diet quality heavily influences these markers, and resultantly our blood fat and cholesterol status should be evaluated at least once a year by a family physician.
A 2016 meta-analysis published by the British Journal of Nutrition reviewed the impact of low-carb vs. low-fat diets on cardiovascular risk factors. The meta-analysis covered eleven randomized controlled trials spanning 1369 total participants who consumed either diet for a minimum of 6 months and was previously healthy. The result of the meta-analysis determined individuals placed on low-carb diets showed positive changes in HDL and triglyceride biomarkers but less favorable changes to LDL cholesterol.
The ketogenic diet or low-carb diet is notorious for its emphasis on saturated fat. Common foods found in low-carb or ketogenic eating are eggs, coconut oil, palm oil, fatty meats, and dairy. While these foods are not exclusively composed of saturated fat, they still contribute a considerable amount of saturated fat to the diet.
Increased saturated fat may be one of the mediators in the etiology of heightened LDL cholesterol. Physicians use LDL as one of the first indicators of arterial plaque formation used to predict CVD risk.
Research into the specificities of LDL cholesterol in the context of low-carb dieting reveals a common discordance between LDL concentration with LDL particle size and LDL particle number. A study by the Journal of Clinical Lipidology shows that LDL particle size is considered a more precise indicator of CVD risk. Another review posted four years later suggests those with low particle numbers may also have a much lower risk of having future cardiovascular events.
While this is excellent news for those seeking to understand a lipid battery report from their latest blood requisition, Canadian medical standards have not yet adopted LDL particle testing. The Canadian panel currently consists of LDL-C, HDL-C, Triglycerides, Non-HDL cholesterol, and Total Cholesterol.
Not knowing the characteristics of the LDL particle means Canadians are mostly in the dark about whether expected rises in LDL should be considered a moot point for CVD development.
In a reference manual released in 2016, the Canadian Cardiovascular Society acknowledges the importance of LDL particle size:
“Moreover, triglyceride replacement of cholesterol on LDL occurs with elevated triglyceride levels, meaning reported LDL-C levels do not reliably indicate LDL particle number when triglycerides are > 1.5 mmol/L.”
Despite the newfound advancements in LDL testing, only privately-run labs offer particle testing to Canadians. Those living in Quebec, Ontario, and Manitoba have access to the NMR Lipoprofile by Dynacare.
Another consideration is that most medical doctors will not be fully proficient in reading advanced cholesterol reports as they are not standard in the Canadian medical model.
In conjunction with the analysis of LDL particles, we should also consider how the rest of our diet impacts arterial plaque formation. In a 2010 article released by the Journal of Lipidology, researchers showcased the associations between dietary antioxidants and their protection against the oxidation of LDL particles, thereby decreasing CVD risk.
Eating a low-carb diet bears the potential to increase LDL cholesterol despite favorable changes to HDL and triglycerides. Increases in LDL are less contentious as a CVD risk factor if the rise in LDL occurs in conjunction with improvements in LDL particle size and decreases in the total number of LDL particles. To assess this, one requires advanced cholesterol testing. Canadians looking for such tests need to order them through privately run labs and seek a forward-thinking practitioner who can interpret these values accurately.
These advances in cholesterol testing also call into play a need for updates to the Canadian model for dyslipidemia diagnosis. While eating a low-carb diet may still confer benefits to CVD risk factors for some, this confirmation is more challenging without advanced testing in the presence of elevated LDL.
Long term consumption of low-carb high-fat diets remain contentious for CVD risk factors. One may improve chances of positive long-term associations on CVD risk when eating a low-carb diet which is also rich in antioxidants. Those following low-carb diets should seek to consume a dietary fat profile which impacts lipid biomarkers positively.
The Low-Carbohydrate Paradigm and Sport
With the rising popularity of low-carb eating strategies, athletes across a broad range of disciplines have started to incorporate low-carb meals into their programs. For athletes who participate in high-intensity sports such as sprinting, weight training, football, hockey, powerlifting, cross fit, weightlifting, and gymnastics, lowering dietary carbohydrates bears the potential to decrease the total storage of fuel required for maximal performance.
The higher the number of fast-twitch fibers required by the athlete, the greater the requirements for glycogen as fuel. Athletes in high-intensity sports who shift to a low-carbohydrate diet may have difficulty sustaining output or fail to reach maximal velocities. These effects in energy production occur when low glycogen status gives rise to reduced ATP manufacture.
Due to its potential implications for athletic performance, caution is required when decreasing dietary carbohydrates for athletes involved in high-intensity sports.
Subscribing to Dietary Dogma
One of the significant criticisms of ketogenic or low-carb eating is the dogmatic or cult style advocates who promote this style of eating. Members of the general public interested in exploring this eating strategy may fall victim to the indoctrination of rules inherent amongst “low-carbers”.
Examples of this are:
“Carbs make me fat.”
“High-fat foods prevent me from gaining weight.”
In the rhetoric promoted by low-carb enthusiasts, one will often encounter the demonization of foods. Foodstuffs like carrots or peas, which contain beneficial phytonutrients, minerals, vitamins, and fiber, are usually off-limits. The rationale is that any dietary carbohydrate has the potential to generate weight regain. When individuals subscribe to these beliefs, they become locked into this way of eating due to the fear of consuming foods contradictory to their goals. Eating in a hyper-restrictive fashion is contentious if one feels unwell, but is too fearful to change their eating patterns.
When determining the best course of action via diet, one should seek to analyze their whole health picture using blood markers, hormone testing, body composition metrics, and health symptoms. To avoid poorly validated rules promoted by advocates of dietary extremes, it is best to seek logic-driven processes to assess one’s whole health picture
The Inclusion of Plant Matter
There is a troubled line of thinking in the ketogenic and low-carb community which suggests that carbohydrate restriction also absolves one of the need to consume vegetables.
While many will excitedly jump the sans-vegetable bandwagon, I’m slightly suspicious of this recommendation.
As a general rule of thumb, the more limited the diet becomes, the more effort one must apply to correct their nutrient deficit. While it’s arguable we can account for the lack of nutrients with supplementation, greens powder, and broths; the question is, how many will apply this level of diligence to their daily diet?
Plant matter comprises a significant daily dose of potassium, magnesium, calcium, vitamin a, vitamin c, iron, folic acid, and fiber. Vegetables are also abundant in plant compounds like phytosterols, Isothiocyanates, flavonoids, phenolic acids, and carotenoids. The synergy of plant chemicals and their relationship to cancer prevention cannot be understated. We do not have the technology to reproduce all of the compounds available in plants. Therefore, consuming a diet in the exclusion of vegetables is not without risk.
Over and above the positive correlations with cancer prevention, we can find an abundance of research supporting the positive effects of vegetables and fiber on CVD risk.
In light of the research supporting the beneficial influence of plant matter, a low-carb diet is likely most health-promoting alongside suitable vegetables such as asparagus, spinach, kale, collard, Swiss chard, kohlrabi, arugula, salad greens, cucumber, celery, radish, and zucchini.
The exclusion of vegetables from a low-carbohydrate diet may generate negative repercussions over the long term. To support long-term health, consume an abundance of low-carbohydrate greens in conjunction with a low-carb or ketogenic diet.