The Truth about the Ketogenic Diet
If you haven’t already jumped on the ketogenic diet craze, I’ll give you a brief overview.
Basically, the ketogenic diet (Keto Diet) is super high in fat (80% of your diet is fat), a super low carbohydrate (<5% of your diet) and moderate in protein (15-20% of your diet). Clearly, not the most balanced of diets considering our diet should contain approximately 20-35% of protein, 45-65% of carbohydrate and 10-35% of fat. So how do you meet that macro-nutrient distribution? Well, you load up on ketogenic diet staples like meat, fish, butter, eggs, cheese, heavy cream, oils, nuts, avocados, seeds and low carbohydrates green vegetables. These kinds of restraining diets tend to make nutrition professionals run for the mountains, but I’m going to give it my honest unbiased interpretation.
The ketogenic diet puts the body into a metabolic state known as ketosis. When your body is in a state of ketosis, the liver produces ketones which become the main energy source for the body.
When you eat something that is high in carbs (that whole large bagel), your body will produce glucose and insulin. Glucose is used as energy so that is why it's the preferred energy source for your body. Insulin is produced to process the glucose in your bloodstream by transporting it around your body. This sounds efficient, right?
The problem with this is that when glucose is used as a primary energy source, fats are not needed for energy and therefore stored. In an average person's diet, glucose is the main energy source. This initially doesn't seem like a problem until you realize that the body can't store that much glucose. This becomes an issue because the extra glucose gets converted into fat which is then stored. Because your body uses glucose as its main energy source the glucose that is converted into fat doesn't get used. When your body runs out of glucose it tells your brain you need more so you end up reaching for a quick snack like a doughnut.
When you lower your intake of carbs, the body begins to look for a substitute energy source and your body enters a metabolic state known as ketosis. You've probably heard of the fact that you can go weeks without food but only a couple of days without water. The reason for this is ketosis. When your body is in a state of ketosis, it produces ketones. Ketones occur from the breakdown of fat in the liver. You might be thinking why isn't the body constantly breakdown fats in the liver? Well, when your body is producing insulin, the insulin prevents the fat cells from entering the blood stream, so they stay stored in the body.
When you lower your carb intake glucose levels, blood sugar levels, drop which in turn lowers insulin levels. This allows the fat cells to enter the bloodstream and head to the liver.
This is the end goal of the keto diet. You don't enter ketosis by starving your body. You enter ketosis by starving your body of carbohydrates.
What should you know before you try the keto diet?
Since research on the keto diet is limited and inconclusive, it’s important to educate yourself about the potential risks before trying it.
Here are things you should know before going keto:
1. Keto diet meal plans are restrictive.
Keto dieters eat mostly meat, healthy fats, and non-starchy vegetables like leafy greens. And...that's pretty much it.
Here's a breakdown of keto-friendly foods, foods that are OK to eat occasionally, and foods keto eaters avoid.
· Fats: Olive oil, coconut oil, butter, avocado oil, MCT oil, avocados
· Proteins: Beef, poultry, eggs, fish
· Non-starchy veggies: Leafy greens, cruciferous veggies (broccoli, cabbage, cauliflower, Brussels sprouts), cucumbers
Keto foods to eat sparingly:
· Full-fat dairy: Milk, cheese, yogurt
· Medium-starchy veggies: Carrots, beets, parsnips, peas, artichokes, potatoes
· Legumes: Beans, chickpeas, lentils, peanuts
· Nuts and seeds: Almonds, cashews, walnuts, pumpkin seeds, sunflower seeds
· Fruits: Berries, bananas, melons
Keto foods to avoid:
- All types of sugar: Including honey, agave, maple syrup
- Grains: Wheat, oats, all types of rice, corn
- All foods made with flour: Breads, pastas, crackers
- Processed foods: Anything that comes in a bag or a box
Despite how limiting the ketogenic diet is, with careful planning, you can still fit in all your vital vitamins and minerals.
2. The long-term effects of the keto diet are unclear.
When you eat refined carbohydrates or just too many carbs in general, the blood is flooded with excess insulin. This can lead to a blood sugar rollercoaster that stresses the body and negatively impacts energy levels and mood. When you’re in a state of ketosis, however, ketone bodies don’t require insulin to cross the blood-brain barrier, which wards off unfavorable blood sugar levels. However, long-term accumulation of ketones could be harmful. Those ketones are emergency fuel sources, and we’re not meant to run on them long-term. Ketones are negatively-charged molecules, which means they’re acidic. When you build up ketone bodies in your system, you’re building up acid. One of the ways your body buffers acid is by pulling calcium from your bones. Also, that the diet isn't very balanced and involves a very high intake of animal products, which generally do not protect against cancer, diabetes, or other diseases.
An important note about the keto diet is that there is a difference between nutritional ketosis (not dangerous) and diabetic ketoacidosis (dangerous – we see people in the ER and it’s potentially life-threatening!). Nutritional ketosis leads to ketone levels of 0.5 to 3.0 mmol/L whereas diabetic ketoacidosis leads to 10-20+ mmol/L.
3. There's a thing called the "keto flu"—and it's not fun.
Carbs hold fluids in your body (think of how bread soaks up water), so when you cut back on carbs, extra water is excreted in your urine. This makes it essential for those on the keto diet to stay hydrated. Not only will drinking extra water help prevent constipation, but it can also lower the odds you'll get of fatigue, headaches, and pain, often caused by dehydration and loss of electrolytes.
Other side effects of the diet may include an increased risk of kidney stones (due to dehydration and acidic urine that’s high in calcium), bad breath, muscle cramps, and dizziness. Further, depending on how you choose your fats, the keto diet can also contain an abundance of saturated fat, which raises levels of dangerous LDL (bad) cholesterol and causes atherosclerosis, the buildup of fats and cholesterol in the arteries.
In my opinion you should still try to lose weight first by following a well-balanced diet full of fruits, vegetables and whole grains. But, to be honest, I’m flexible on the ketogenic lifestyle, especially if you’re following this diet with the help of a Nutritionist.
Clearly, the ketogenic diet is restrictive and isn’t for everyone. Be realistic about whether this diet will align with the lifestyle you want. If you have a sweet tooth or love your fruits and veggies, you will likely struggle on keto. Those who are vegetarian, or vegan will also find the ketogenic diet challenging.
By: Carol Aguirre MS, RD/LDN