The Truth About Ketogenic Dieting: What to Know Before You Start

You may have heard about the popular ketogenic diet, often simply called the keto diet. It involves eating a lot of fat, a medium amount of protein, and very few carbohydrates.

Eating this way changes the kind of fuel your body uses for energy. It also changes the way your body gets and uses that fuel. Adopting this low-carb lifestyle means leaving many healthy foods out of your daily meals.^1-7

Your body is naturally made to use carbohydrates for energy. On a keto diet, it must use something else.

The idea is that without carbs, your body will use stored fat for energy. Your liver turns body fat into a fuel called ketones, shifting your body into a metabolic state known as ketosis. These ketones become the energy source for your heart, kidneys, muscles, brain, and body functions.^1-7

Keto fans report losing a lot of weight. But there are few long-term studies about whether people keep the weight off over time.

Weight loss is not the only thing that happens to your body when you adopt this diet. There are serious physical and mental effects to think about before you decide whether to try it.^1-7

Understanding the side effects of the keto diet

At first, you are likely to have the “keto flu.” These effects can make it hard to complete daily tasks, though they often pass after 2 to 4 weeks. During this initial transition into ketosis, you may experience symptoms such as:^1-3

• Feeling tired or fatigued
• Dizziness
• Nausea or feeling sick to your stomach
• Headaches
• Trouble thinking, commonly called “keto fog”

To restrict carbohydrates, you avoid foods like whole grain breads, fruits, legumes, and starchy vegetables. But these foods are full of important vitamins, minerals, and fiber that your body needs. Missing out on these nutrients can be a concern, as they help protect against many health conditions, including:^1-3

• Heart disease
• Diabetes
• Cancer
• Alzheimer’s disease
• Malnourishment

When you do not eat enough carbohydrates, your body may not get all the nutrients it needs to stay healthy.^1-3

What scientific research says about long-term low-carb safety

The best studies test large numbers of people over a long time. At this point, the only long-term ketogenic diet studies are about treating epilepsy.

That is why few experts recommend it for weight management. Also, some studies report serious concerns about the long-term effects of the keto diet, highlighting an increased risk of:^1-5,7

• Dehydration
• Kidney stones and chronic kidney disease
• Plaque in the arteries and stroke due to high “bad” cholesterol (LDL) levels
• Liver disease
• Diabetes (in the long term)
• Gestational diabetes or birth defects if a low-carb lifestyle is followed before and during pregnancy
• Alzheimer’s disease

In some studies, few people stayed with the diet long term. Many people also found it hard to keep the weight off after stopping the diet.^1-5,7

However, other studies promote the keto diet for short-term help with certain health issues. They found the diet can have positive effects including:^3,6,8

• Weight loss (typically within the first 6 to 12 months)
• Appetite control
• Blood sugar control
• Healthy blood levels of neutral fats (triglycerides)
• Increased “good” cholesterol (HDL)
• Improved memory in the short term for a few people with Alzheimer’s disease
• Improved stamina in sports
• Stopping seizures in people with epilepsy when medicine does not work

How to safely navigate macronutrients and meals

If you are interested in starting a ketogenic diet, it is important to consult a healthcare provider first. You will need to learn to keep track of your macronutrients (macros). You also may want to talk to a nutritionist to help you map out your meals.^1-5,7

Keto diet plans vary in the exact amounts of macros they require. Below is a sample daily breakdown for an average person who eats 2,000 calories per day.^1-3,5

• Fat: 75 to 80 percent of calories (1,500 to 1,600 calories). This is about 165 to 178 grams per day.
• Protein:15 to 20 percent of calories (300 to 400 calories). This is about 75 to 100 grams per day.
• Carbohydrates:5 to 10 percent of calories (80 to 160 calories). This is about 26 to 52 grams per day.

Here are some types of foods this low-carb lifestyle commonly includes:¹

• Dairy products such as butter, cream, cheddar or Gouda cheese, whole-milk plain Greek yogurt, cottage cheese, and sour cream
• Eggs
• Nuts and seeds
• Olive, coconut, and avocado oils
• Red meat, pork, poultry, and fatty fish such as salmon, tuna, and cod
• Vegetables that grow above ground like zucchini, squash, tomatoes, and peppers

Before you begin, talk to your healthcare provider, do your homework, and consider the pros and cons of the ketogenic diet. You can learn more about it online, where youwill find keto websites, diet plans, recipes, and shopping tips.