The Truth About the Keto Diet and Weight Loss

The Truth About the Ketogenic Diet and Weight Loss
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Kamal Patel is the director of, an independent and unbiased encyclopedia on supplementation and nutrition. He is a nutrition researcher with an MPH and MBA from Johns Hopkins University, and is on hiatus from a PhD in nutrition, in which he researched the link between diet and chronic pain. He has published peer-reviewed articles on vitamin D and calcium as well as a variety of clinical research topics.

Not too long ago, many health-conscious eaters were intent on avoiding dietary fat like the plague. Today, many among that crowd — celebrities and athletes included — are pulling a 180 instead. Fat is in, and sugar and carbs are out. In the name of weight loss and improved health, high-fat, low-carbohydrate diets have become the new ‘it’ nutrition plans. The cream of the crop: The ketogenic diet. So why is it so appealing, and does it deliver real results? Let’s dig in.

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The Ketogenic Diet: The Metabolic Benefits?

When you adopt a ketogenic diet, you replace the majority of calories (about 80 percent) in your diet that come from carbohydrates and protein with fat. Carbohydrates are the main source of fuel for your cells, so eating a low-carbohydrate diet forces your body to rely on its reserves (aka glycogen). As glycogen levels fall, the body begins to rely more heavily on fat and its by-products, known as ketone bodies, for energy.

Because glycogen is stored with water, people typically lose a lot of body weight in the first week or two after adopting a ketogenic diet. But ketogenic diets don’t lead to more fat loss in the body when you consume the same amount of calories as you do with carbohydrates. People only begin to shed fat when they have a calorie deficit. So what’s the secret to making the ketogenic diet work for weight loss?

RELATED: Why You Should Eat More Fat and Less Sugar

How Much Fat Is Too Much?

By increasing the amount of fats in your diet (more specifically from 30 to 80 percent of your daily calories), your body will hit a state of ketosis — meaning it relies on ketone bodies for fuel. So for someone who consumes 2,000 calories a day, that would be 178 grams of fat (one gram of fat is equal to 9 calories). To put this into perspective, in a normal, healthy diet, the American Heart Association recommends limiting fat to no more than 20 to 35 percent of your total daily calories. That’s only 44 to 78 grams of fat each day versus 178.

Ketosis affects the hunger hormones (ghrelin and leptin), which may result in decreased appetite and thus fewer calories consumed. Proponents of the ketogenic diet also claim that dietary fat stored in the body is more efficient as an energy source than carbohydrates. But research shows that a diet with little-to-no carbs can result in poor sports performance. (And who wants that?) So do make sure you’re not going cold turkey on carbs completely.

To reap the benefits of a ketosis, that also means incorporating high-quality fats from whole-food sources (not loading up on processed foods or oils straight from the Taco Bell drive-through). Instead, think: nuts and seeds, avocados, olives, fatty fish and dairy. These foods not only provide higher quality fats, they deliver vitamins and minerals necessary for better overall health and activity.

RELATED: The Ultimate Guide to Pre- and Post-Workout Carbohydrates

The Drawbacks of Going Keto

Some people who follow the ketogenic diet may experience adverse effects, such as dehydration, bad breath and digestive issues. Sports performance may also be impaired by the diet, especially at higher intensities, because carbohydrates are more efficient at producing the energy required to fuel these types of workouts. But research shows that a ketogenic diet may help with ultra-endurance races because of the high reliance of these long races on fat as a fuel source.

The bottom line: The ketogenic diet doesn’t actually produce any special metabolic effects. But if you want to lose weight and cut back on carbohydrates, the diet can help reduce your appetite. Interested in giving the ketogenic diet a try? Speak to your doctor and nutritionist to see if it’s the right fit for you.

Read More:
What 5 Days of a High-Fat Diet Does to Your Muscles
Coconut Oil: Should We Worry About Saturated Fat?
The Truth About How to Lose Belly Fat

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