Can High-Fat Keto Diet Be Good For You? (2025)

The ketogenic (keto) diet is everywhere these days, trending on recipe sites and in magazine articles. Proponents claim the high-fat diet helps you quickly shed pounds while indulging in foods that are normally off limits in other diets: bacon, cheese, nuts, whole-milk dairy and butter.

Sounds pretty amazing, right? But before you run to the grocery store to stock up on avocadoes and cream, you should know what you’re getting into, says Genevieve Kruzick, RD, CD, a clinical dietician at Franciscan Health in Lafayette, Indiana. Here, she answers questions about the diet, and its pros and cons:

How Does the Keto Diet Work?

There are three sources of fuel your body uses for energy: carbohydrates, proteins and fats. Carbohydrates are broken down into glucose, or blood sugar, and are your body's primary fuel source. When carbohydrates aren't available, your body relies on fat for energy. Protein is the main building block for muscles and tissues. In a pinch, protein can also be converted to glucose and used for energy.

The keto diet forces your body to use fat as its main energy supply instead of glucose, a process called ketosis. On the keto diet,you eat so few carbohydrates that your body can't rely on glucose for energy. And since keto meals are loaded with fat, your body switches over to using fat for energy instead of carbohydrates. You get 70 to 80 percent of your calories from fat, 15 to 20 percent from protein and about 5 percent from carbohydrates (for a total of 20 to 30 grams of carbohydrates a day, depending on your height and weight).

Is the Keto Diet Plan Different Than Other Low-Carb Diets?

The premise of many popular diets is eating a lower amount of carbohydrates, but most of these diets, including Atkins and Paleo, are also very high in protein. The keto diet plan is different because you only eat a moderate amount of protein. Otherwise, your body would convert protein into glucose and wouldn’t achieve a state of ketosis, where it only uses fat for energy.

Does the Keto Diet Help You Lose Weight?

Yes, you'll lose weight but only because you're consuming fewer calories. There's no real magic to the keto diet. The weight-loss equation remains the same: You lose weight when you consume fewer calories than you use each day. You're not burning more fat than other diets, or at a faster rate. On the keto diet, you eat high-fat meals with protein, which keeps you feeling full for longer and cuts down on your overall eating throughout the day.

Will the Keto Diet Increase Your Cholesterol?

Research indicates that diets that are high in fat, like the keto diet, do not have a negative impact on cholesterol and triglycerides as long as the carbohydrate intake remains very low. In fact, your cholesterol and triglycerides might actually improve, if you're focusing on eating healthy fats like avocado, olive oil and nuts, not loading up on bacon and burgers.

What is the "Keto Flu?"

That's a phrase used to describe symptoms some people experience during the first four to seven days on the keto diet. You may feel exhausted, irritable and have a bad case of brain fog, or inability to focus. Dieters also report feeling nauseous, dizzy and achy.

The keto flu happens when your body switches from using carbohydrates as its primary energy source to processing fats instead, which don't break down as easily. It's a period of adjustment. It's not harmful, and after the phase passes you'll feel better.

Who is a Good Candidate for the Keto Diet?

Before you start the keto diet, talk to your doctor to make sure you're a candidate. For example, those who are pregnant, nursing or have diabetes, need a doctor's approval before moving forward.

Then, you need to ask yourself, is this something I want to do long term, or is there a better way to do this? If you're serious about starting a keto diet, get nutritional counseling. It's not easy to get the nutrients your body needs while keeping your carbohydrates so low.

If you're only allowed 20 to 30 grams of carbohydrates a day, you'll need to scrutinize everything. Even foods you don't traditionally think of as carbs – like broccoli and nuts – contain them. A dietician can work with you to create healthy, ketogenic meal plans.

How Can You Avoid Gaining the Weight Back?

The keto diet is so restrictive, it's difficult to sustain over time. Only people who are truly devoted can maintain that level of diligence when it comes to meal planning, nutrient tracking and eating out. So after losing the weight, most people go back to their old eating habits. Unfortunately, the vast majority of people who try fad diets end up gaining the weight back because they haven't really found a new way to live.

Is There a Better Way to Lose Weight?

I think the quality of carbohydrates you eat is more important than the quantity. Just like you can use fat and protein to fill you up, higher-quality carbohydrates like whole grains and fiber can do the same thing. What's essential is reducing the amount of refined and processed foods you eat that have little nutritional value.

Determining the diet that best suits you is a very individual choice, so it's hard to make a general recommendation for one type of diet. You can lose weight through a variety of eating styles, whether you choose a low-carb, low-fat, keto or Mediterranean diet, or another one. But in general, eating lots of fruits and vegetables, lean proteins and whole grains is going to help you lose weight and achieve a healthy lifestyle.