What is the high-fat low-carb diet? Is it a healthy way to eat? As the name suggests, the diet suggests eating high fat and low carbohydrate foods.
There’s scientific evidence that this eating approach could help you lose weight and shield you from some chronic diseases. There’s also research that suggests a low-carb, high-fat eating regimen can lower your defenses against some chronic conditions and – in the short term – create unpleasant side effects.
What is the low-carb high-fat diet?
There’s no single definition of a high-fat low-carb eating regimen, says Bethany M. Doerfler, a clinical research dietitian in the division of gastroenterology and hepatology at Northwestern Medicine in Chicago. She works in her division’s Digestive Health Center. While there are some well-known eating plans that are low-carb and high-fat – like the keto diet – you need not follow one of those regimens to adhere to this style of eating. You can craft your own low-carb, high-fat eating plan with a registered dietitian. This sort of regimen deviates from the Institute of Medicine’s acceptable macronutrient distribution range, which recommends adults in the U.S. get 45% to 65% of their daily calories from carbs, and 20% to 35% from dietary fat and 10% to 35% from protein.
While individual low-carb, high-fat eating regimens vary, they typically call for obtaining less than 50% of your daily calories from carbohydrates, Doerfler says. Fat intake ranges from between 30% to 40% of daily caloric intake, and protein consumption might land in the 10% to 30% daily range. If you plan on trying a low-carb, high-fat eating regimen, Doerfler recommends consulting a registered dietitian first. He or she can help you develop an eating plan that provides the nutrition you need and can help you attain your health goals.
Can It Be Healthy?
A high-fat low-carb eating approach can be healthy – provided the food choices are smart, says Tasha Temple, a registered dietitian with Northside Hospital in Gwinnett, Georgia. Making healthy choices can reduce the risk of developing chronic diseases like heart disease, diabetes and metabolic syndrome, which includes obesity, she says.
Research suggests that a low-carb, high-fat diet can help you lose weight, which in turn can help ward off chronic conditions like diabetes and heart disease. For example, a meta-analysis of 11 randomized controlled trials involving 1,369 participants suggests that people experience a greater decrease in body weight while adhering to a low-carb, high-fat plan (compared to other eating regimens), according to a study published in the European Journal of Nutrition in March 2018.
Adhering to a low-carb, high-fat eating regimen may increase the number of calories your body burns, research published in November 2018 in the BMJ, a weekly, peer-reviewed medical journal, found. The study involved 164 participants with obesity who had lost up to 14% of their weight during the initial phase of the study while adhering to a weight-loss diet. During the 20-week maintenance phase, the participants were provided different amounts of carbs in their diets. Some received 60% of their daily calories from carbs, while others consumed 40% and members of a third group derived 20% of their daily calories from carbs. The amount of energy expended by the people consuming 20% of their daily calories from carbs was significantly greater than the energy burned by those on the high-carb regimen, researchers found.
High-fat low-carb diets have great potential for fatty liver
A research study published in June 2021 examined the impact of different eating approaches on individuals with nonalcoholic fatty liver disease. Over the course of 12 weeks, researchers examined 74 patients, randomly assigning each a 12-week NAFLD treatment program with one of three approaches: a low-carb, high-fat diet, a 5:2 intermittent fasting diet, or general healthy lifestyle advice and suggestions from a hepatologist.
By the study’s end, researchers noted a higher reduction in steatosis (abnormal fat retention in the liver) and overall body weight in those who followed the low-carb, high-fat diet. Compared to the typical NAFLD lifestyle recommendations given by a hepatologist, a low-carb, high-fat diet offered more promise and potential.
While those who followed the recommendations of a hepatologist focused primarily on eating a healthy diet and controlling calorie intake, those on the low-carb, high-fat diet saw significant decreases in liver fat. That diet also proved more effective in reducing body weight, helping participants shed more extra pounds. On average, the low-carb, high-fat diet led to a 7.3-kilogram weight loss; those who stuck with the hepatologist-advised approach lost just 2.5 kilograms.
In addition to the liver health benefits of the low-carb, high-fat diet, researchers also saw healthy improvements in participants who tried the 5:2 intermittent fasting approach. Those who gave the 5:2 diet a try saw improvements to their cholesterol levels and less liver stiffness, and they lost an average of 7.4 kilograms each. So, there may even be potential benefits to going low-carb, high-fat and trying intermittent fasting at the same time (though it’s important to note the researchers didn’t study this combination of approaches).
Isn’t high-fat low-carb the same as the keto diet?
If you’re wondering why the low-carb, high-fat diet tested in this research study sounds familiar, that’s because it’s pretty popular. It’s a version of the keto diet, just with a different name.
Just like the diet approach mentioned in the above study, the ketogenic diet is all about slashing carbs and upping fat intake. And while it might sound completely counterintuitive to eat more fat when you’re dealing with fatty liver disease, this isn’t the first research to support the idea that a keto-like approach to your diet can have a positive effect on your liver.
A research review published in August 2020 took a look at the benefits of a ketogenic diet in individuals with nonalcoholic fatty liver disease. While there’s been hesitancy about a fat-rich diet, the authors of this review noted that ketone bodies were a potential boon for inflammation – one of the key concerns for those with NAFLD. It’s hypothesized that a keto approach can help NAFLD patients lose weight, reduce inflammation and potentially offer additional benefits through ketosis. And it’s thought that the low-carb component of a keto diet may be what has the biggest impact.
While more in-depth research is needed, a keto diet could help you target two of the most critical factors in developing fatty liver: inflammation and being overweight. But is a high-fat diet really a good idea for people who are dealing with fat buildup in the liver?
Which foods can I eat on the LCHF diet?
While the risks of consuming a low-carb, high-fat diet are genuine, such a regimen can be healthy if you make the right food choices, Temple says.
Specifically, consuming proteins that include lean meats, chicken and fish, non-starchy vegetables and healthy fats that are low in saturated fats could comprise a healthy eating regimen, she says. You should also stay away from highly processed offerings, says Tammy Ward, a registered dietitian with UC Health, the health system affiliate of the University of Cincinnati. Highly processed foods include bacon, cold cuts, and snack foods like chips, cookies, pies and cupcakes. Conventionally, these foods also contain more carbs than recommended on low-carb diets. If you want to indulge your sweet tooth and prefer healthy options, there are many recipes online utilizing whole food ingredients, such as almond and/or coconut flour, cocoa powder and nut butter for creating new low-carb “sweet” treats, Ward says. The primary higher-carb foods to avoid or strictly limit are grains, starchy vegetables and sugars.
Here are healthy foods you can eat on a low-carb, high-fat diet:
- Meats (other than bacon, sausage and hot dogs).
- Peanut butter.
- Nut butters.
- Olive oil.
- Legumes (in limited quantities).
- Dark, leafy salads.
- Non-starchy vegetables, such as spinach, Brussels sprouts, broccoli, cauliflower and cabbage.
It’s important to keep in mind that some low-carb, high-fat diets don’t distinguish between highly refined, processed carbs from offerings like candy, cookies and potato chips and high-quality carbohydrates that come from much healthier sources such as legumes, whole grains and fruits, says Lisa Garcia, a registered dietitian based in Laconia, New Hampshire.
Consuming enough fiber is important in maintaining a healthy gut microbiome, the typically diverse mix of microorganisms that live in our guts. A healthy and diverse microbiome supports the immune system, research suggests. The gut microbiome may also be linked to mental health and digestive wellness, studies suggest.
Dietary fiber is also important in maintaining regular bowel movements. High-fiber foods add a feeling of fullness, which is essential to losing pounds or maintaining a healthy weight. Insufficient fiber could lead to constipation.
To make sure you get enough fiber, Garcia recommends consuming some foods that would be prohibited or limited under some low-carb regimens, like legumes.
Adding non-starchy vegetables to meals and snacks would also help you meet your daily fiber requirements, Jones says. “It’s a best practice to make half of your plate vegetables when trying to meet your daily fiber requirement,” Jones says. “This goal can be accomplished by adding non-starchy vegetables to meal and snack choices throughout the day.”