The Low Carb Ketogenic Diet Demystified
If you've stumbled upon my blog, you may now be asking yourself what is keto?
In short, it's a diet that doesn't suck. Before we dive into the details of how that can be humanly possible, let's talk about this word "diet" for a second.
Diet has become such an ugly word. Not for what it means, but for the way it makes people think and feel.
As we explore the ins and outs of the ketogenic diet, think of it more as a healthy way of eating and less of a diet to avoid the negative connotations associated with that dreadful four-letter word. Diets suck, keto doesn't.
- What is Keto?
- Understanding Ketosis
- How to Get Started with the Keto Diet
- What Happens During Nutritional Ketosis?
- Benefits of Low Carb Ketogenic Diet
- Potential Cons of Ketogenic Diet
- Who Should Avoid a Ketogenic Diet?
What is Keto?
A ketogenic diet, or “keto” as many now refer to it, focuses on eating real, whole foods that are very low in carbohydrates. This very low carb diet keeps sugary and starchy foods to a minimum while providing your body with the nutrition it needs through adequate protein and dietary fat intake. By eating this way, you will quite literally change your metabolism (the way your body processes food). Instead of burning primarily sugars for fuel, your body will start burning fat as the preferred fuel source. I like to call it “fat burning mode” because it sounds cool, but it’s more commonly referred to as KETOSIS.
Ketosis is the state of using fat and protein as a fuel instead of carbohydrates. To better understand, let's look at the three main types of carbohydrates found in food:
- STARCHES (complex carbs)
- SUGARS (simple carbs)
Sugars are simple carbs. They are quickly digested and instantly spike your blood glucose. This leads to the notorious sugar rush, followed by the inevitable sugar crash, all while taxing your pancreas and elevating insulin levels. Most of us have been advised to stay away from simple sugars. Generally, everyone agrees that sugar is not good for your health and should be avoided.
[color-box color="red"]Examples include: white sugar, refined foods, juices, sweetened beverages.[/color-box]
Starches take a little longer to digest because they are broken down into simple sugar first, leading to a slower rise in blood glucose levels. This delayed rise in blood sugar has led to the belief that starches are "good carbs" in many other diets. However, the body actually treats sugars and starches very similar, so both must be avoided on a low carb ketogenic diet.
The body prefers to burn glucose for energy when it is available; but when excess carbs are eaten, the body does not have immediate use for all of the extra glucose. This triggers high levels of insulin, which causes the body to store the extra energy as fat. High levels of insulin also prevent the release of fat from fat cells and is linked to a host of other metabolic disorders.
[color-box color="red"]Examples of starch-rich foods include: Potatoes, wheat bread, wheat pasta, rice, quinoa, corn.[/color-box]
Fiber, on the other hand, is the only carbohydrate that does not impact the blood sugar. A low carb ketogenic diet encourages more fiber intake for this reason. When consumed, dietary fiber is mostly passed through the digestive system instead of being broken down, contributing more to digestive health rather than nutrition. Fiber keeps you regular and does not contribute to your total carb count. You can eat as much fiber as you want (and should!) on a low carb ketogenic diet.
[color-box color="green"]Examples of fiber-rich foods include: lettuce, bean sprouts, cabbage, artichoke, spinach, brussels sprouts, asparagus[/color-box]
How to get started with the keto diet
For beginners, your goal should be to eat 20 grams or less of net carbohydrates per day. This isn't a hard and fast rule (carbohydrate tolerance varies from person to person), but it's a good starting point for most people to keep their carb intake low enough to make the metabolic shift to nutritional ketosis. This means that you will need to avoid sugary/starchy food including: sugar, pasta, bread, flour, and most fruits. You'll also need to be aware of your macros. If you have a blank look on your face right now and thinking, "BUT WHAT ARE MACROS?!", be sure to read my post about it here.
You may be able to gradually increase carbs up to 50 grams or less per day, but the idea is to remain in ketosis continuously and become keto adapted -- not to return to a high carbohydrate diet.
By becoming familiar with the carbohydrate content of different foods, you will quickly learn how to adjust your eating for success on the keto diet.
It’s important to note that while a ketogenic diet is definitely low in carbs, it is not fundamentally a "NO" carbohydrate diet. Although some do prefer to aim for zero carbs, you don't necessarily have to get that low to reach ketosis. You can certainly eat your veggies, folks! (Especially your greens - check out the searchable/sortable low carb vegetables list for more insight!) Nutritional ketosis relies on limiting carbohydrates, but not eliminating them entirely; none is not necessarily better than some.
What happens during NUTRITIONAL KETOSIS?
When you maintain a minimum carbohydrate intake, your body adapts from burning glucose for energy and readily releases fat from fat cells. The fat (triglyceride) is broken down into 3 fatty acid molecules and one glycerol molecule. Most of the cells in your body can, and do, burn the fatty acids for fuel. Through further metabolism, the liver creates ketones, which your cells use for metabolism. This process is known as nutritional ketosis.
Nutritional ketosis is fine — it just means that your body is burning fat. (Ketosis is commonly confused with ‘ketoacidosis’- a serious condition that can occur in individuals with diabetes.) Ketosis is a completely normal mode of metabolism when carbs are restricted. Your body flushes the excess ketones from your system via respiration and urination.
After a while, your body will become very efficient at burning ketones as the primary fuel source and you will become what is known as "keto adapted" or "fat adapted". Your hunger will decrease significantly, and if you have extra weight on your body, you will eat less and lose weight. It’s pretty cool.
If you are curious, you can measure your urine or blood ketones at home with urinary or blood ketone test strips. When you are just starting out, you may find this helpful confirming that you are in ketosis... but it's really not necessary (or even recommended). Once your body becomes fat adapted, ketones are burned much more efficiently and excess ketones don't spill into the urine. That means not everyone will have measurable ketones in the urine even when they are successfully fat-burning and losing weight. So if there are no ketones in the urine, it does not necessarily mean that you are not burning fat. (TL;DR: don't waste your money on ketostix)
Benefits of Low carb ketogenic diet
Reduces your appetite: Once you begin a ketogenic diet, you will notice that you do not get hungry like before. On many restrictive diets, you feel constantly deprived and hungry. The constant hunger typical of many diets is one the reasons the word diet has such negative undertones. It’s a terrible feeling! You either cheat or give up completely just to feel better and never make any sustainable progress on your weight loss. But not if you follow the keto way of eating! Luckily, a side effect of being in ketosis is decreased appetite. (1, 2) Ketosis brings your hunger pangs to a screeching halt, which is one of the reasons it is so easy to stick to the ketogenic diet. You can break the cycle of deprivation, binging and subsequent guilt with the keto diet pretty easily because that ravenous hunger never sets in.
Weight loss: One of the most popular reasons for starting a low carb ketogenic diet is weight loss. Within a couple weeks (or sooner) of reducing your carbohydrate intake, you will notice the number on your scale declining and your clothes getting looser. Studies show that low carb diets are more effective for weight loss than low fat diets. (3) That’s right; we’ve been doing it wrong. And as for that ever-present “water weight” we all carry around? Say goodbye to that. For every gram of glycogen (stored form of glucose) there are 4 molecules of water attached. Since the keto diet does not supply huge amounts of carbohydrates, water retention weight is drastically reduced. No more bloated feeling!
Improved body composition: It’s important to note the difference between weight loss and fat loss. Weight loss is simply a decrease in your overall weight, while fat loss is targeted directly at your fat stores without affecting your muscle. Muscle loss is a very bad thing, so you want to make sure that you are losing the right kind of weight… the weight from excess fat! Very low carb diets have been shown to decrease fat mass while sparing lean body mass (4). This means that keto will burn your existing fat stores without decreasing muscle.
Blood pressure reduction: If you have high blood pressure, this diet helps to bring it down. Low carb diets have been proven to be very effective in reducing blood pressure levels. (5)
Improved Insulin Levels: If you are overweight and diabetic, you have a double-benefit following the keto way of eating. The ketogenic diet has shown notable improvements for patients with insulin resistance (7). The nature of the diet leads to a drop in insulin levels, no more elevated insulin! Diabetes, pre-diabetes, metabolic syndrome, PCOS and a host of other conditions that are affected by out of whack insulin levels may be alleviated by making different food choices.
Healthy blood cholesterol and triglyceride levels: Yet another remarkable benefit of a low carb ketogenic diet backed by many studies is its ability to bring blood cholesterol levels to a healthier state. A 2010 study published in the Journal Archives of Internal Medicine revealed the improved cholesterol and triglyceride levels of study group that followed a keto diet. The study showed that the levels of good cholesterol (HDL), triglycerides (3) and bad cholesterol (LDL) improved to healthier levels when participants followed a ketogenic diet. What was more impressive about the observation is that the improvement of these blood parameters were more significant than the group that took medication. Point to keep in mind: “bad” cholesterol is not caused by consumption of fat. Researchers have actually linked high LDL to a high carbohydrate diet. (3)
Naturally gluten-free: If you have issues with gluten and grain, then a low carb ketogenic diet is your best choice. The keto diet eliminates gluten and grains by default. The diet offers all the benefits associated with gluten-free/grain-free diet.
Treatment of Epilepsy: Ketogenic diets have been used since the 1920s in response to the observation that fasting had anti-seizure properties. Ketosis mimics the metabolic state that happens when fasting, producing ketone bodies, which have preventive effects on seizures. A 2005 paper published in Epilepsy behavior states that the ketogenic diet has significant potential as a power tool for fighting epilepsy. (6, 8, 9)
Treatment of PCOS: Polycystic ovarian syndrome (PCOS) is the most common endocrine disorder affecting women of reproductive age. It is associated with infertility, obesity, high insulin levels, and insulin resistance. Because ketogenic diets have been shown to reduce insulin resistance, it is often recommended for patients that suffer from PCOS. Keto is beneficial to such patients as it leads to a significant improvement in body weight, percent free testosterone, LH/FSH ratio, and fasting insulin levels (10). I personally manage my PCOS symptoms through a ketogenic diet with great success.
May help treat neurodegenerative disorders: Ketosis is proposed to be beneficial in neurodegenerative conditions like Alzheimer’s and Parkinson's. Researchers propose several mechanisms that may promote better neurological functions in patients that suffer from these disorders. This includes improved resiliency of nerve cells, altered brain pH, and synthesis of neurotransmitter GABA -- all of which seem to benefit patients with neurological conditions. (11)
Potential cons of ketogenic diet
The "Keto Flu": When adapting to a ketogenic way of eating, you may experience temporary flu-like symptoms, like nausea, headache, cramps and fatigue. These temporary discomforts are referred to as ''keto flu”. Once your body adjusts to the new changes these symptoms generally disappear.
But! There are measures that you can (and should) take to prevent these symptoms from ever happening – including staying hydrated and increasing your salt/electrolyte intake.
To combat: Drink water and increase salt, magnesium, and potassium!
Weird taste in mouth: “Fruity breath” is a very common side effect of following a low carb ketogenic diet, caused by the acetone by-products of ketosis. Not all ketoers experience this, but if it occurs the best remedy is to drink plenty of water. The reduced appetite may also lead to lowered water intake, which can lead to dehydration related bad breath.
To combat: Maintain good oral hygiene and stay hydrated!
Not eating fiber-rich greens: Some people assume that a ketogenic diet is a complete NO carb diet and do not consume mineral-rich and vitamin-rich green leafy vegetables such as spinach or chard. Leafy greens contain very few carbs (most of which are fiber) and are chalk full of nutritional value. Not adding enough greens and veggies into your diet can lead to constipation and irregular bowel movements.
Who should avoid a ketogenic diet?
As with most things, one size does not fit all. While it is understood that ketosis is not harmful for most people, there are several medical conditions that are contraindicated for a ketogenic diet. As always, consult your physician before starting a diet and exercise program.
Anyone who has been diagnosed with the following should avoid ketogenic diet:
- pyruvate carboxylase deficiency
- impaired renal (kidney) function
- rare genetic disorders of fat metabolism
- Johnstone, A.M., Horgan, G.W., Murison, S.D., Bremner, D.M., Lobley, G.E. (2008). Effects of high-protein ketogenic diet on hunger, appetite, and weight loss in obese men feeding ad libitum. The American Journal of Clinical Nutrition. 87 (1), 44-55.
- Gibson, A.A., Seimon, R.V., Lee, C.M., Ayre, J., Franklin, J., Markovic, T.P., Caterson, I.D., Sainsbury, A. (2015) Do ketogenic diets really suppress appetite? A systematic review and meta-analysis. Obesity Reviews. 16 (1), 64-76.
- Yancy, W. S., Olsen, M. K., Guyton, J. R., Bakst, R. P., & Westman, E. C. (2004). A low-carbohydrate, ketogenic diet versus a low-fat diet to treat obesity and hyperlipidemia: a randomized, controlled trial. Annals of internal medicine, 140(10), 769-777.
- WESTMAN, E. C., & Volek, J. S. (2002). Very-low-carbohydrate weight-loss diets revisited. Cleveland Clinic journal of medicine, 69(11), 849.
- Yancy WS Jret.al. A randomized trial of a low-carbohydrate diet vs orlistat plus a low-fat diet for weight loss.A. Arch Intern Med. 2010 Jan 25;170(2):136-45. doi: 10.1001/archinternmed.2009.492.
- (b)Bailey EE1, Pfeifer HH, Thiele EA. The use of diet in the treatment of epilepsy. Epilepsy Behav. 2005 Feb;6(1):4-8.
- Veech, R. L. (2004). The therapeutic implications of ketone bodies: the effects of ketone bodies in pathological conditions: ketosis, ketogenic diet, redox states, insulin resistance, and mitochondrial metabolism. Prostaglandins, leukotrienes and essential fatty acids, 70(3), 309-319.
- Neal, E. G., Chaffe, H., Schwartz, R. H., Lawson, M. S., Edwards, N., Fitzsimmons, G., ... & Cross, J. H. (2008). The ketogenic diet for the treatment of childhood epilepsy: a randomised controlled trial. The Lancet Neurology, 7(6), 500-506.
- Sirven, J., Whedon, B., Caplan, D., Liporace, J., Glosser, D., O'Dwyer, J., & Sperling, M. R. (1999). The ketogenic diet for intractable epilepsy in adults: preliminary results. Epilepsia, 40(12), 1721-1726.
- Mavropoulos, J. C., Yancy, W. S., Hepburn, J., & Westman, E. C. (2005). The effects of a low-carbohydrate, ketogenic diet on the polycystic ovary syndrome: a pilot study. Nutr Metab (Lond), 2, 35.
- Barañano, K. W., & Hartman, A. L. (2008). The ketogenic diet: uses in epilepsy and other neurologic illnesses. Current treatment options in neurology, 10(6), 410-419.