Is a Low-Carb, Low-Fat Diet Still a Valid Weight Loss Program?

Low-carb and low-fat diets have gained popularity as possible methods for weight loss. This has led many people to wonder if combining the two into a single low-carb, low-fat diet is possible. However, there’s almost no evidence to support that such a diet would be beneficial. Here’s what you need to know. 

Low-carb and low-fat diets are two popular weight-loss strategies that have been around for decades. Both approaches have their proponents and critics, and it can be difficult to know which is best for you. However, research shows that low-carbohydrate diets may be better for weight loss.

Low-carb diets involve eating plans that purposefully reduce your overall intake of carbohydrates. Usually, carbs make up 45% to 65% of your daily macronutrient balance — however, low-carb diets attempt to reduce this number to less than 26%. Proponents of these diets claim this approach increases satiety levels while lowering your overall caloric intake. 

The most popular low-carb diets are:

• Keto diet
• Atkins diet
• Paleo diet
• South Beach diet

Various studies show that low-carb diets are effective for weight loss, causing a rapid decrease in weight during the first year. While some of this lost weight comes from water loss, low-carb diets also cause a significant reduction in the fat in your body. After the initial year, though, low-carb eating plans often become less efficient.

Low-fat diets attempt to reduce your daily fat intake to 30% of your macronutrient balance. These diets are popular due to their health benefits, such as lowering your risk of cardiovascular disease and cancer. Popular low-fat diets include:

• Ornish diet
• Pritikin diet
• TCL diet

Contrary to popular belief, though, low-fat diets don’t seem to be as effective as low-carb diets when it comes to losing weight. For example, a 2004 study put participants on one of these diets for 24 weeks. At the end of the trial, the low-fat diet group lost, on average, 6.7% of their weight. The low-carb group, on the other hand, showed a 12.9% reduction in their body weight.

Given the effectiveness of both diets, many people wonder if you can combine both into a single low-carb, low-fat eating plan. While it’s possible to create a diet that only contains protein-rich foods, there’s little evidence to support its potential effectiveness. On the contrary, experts suggest that following such a nutritionally unbalanced diet might not even be safe.

Macronutrients are the cornerstone of your diet, providing most of the energy and building blocks your body needs to be healthy. Each of the three macros has its own functions, making it essential to maintain a correct balance between them. 

These are some of the most basic roles of each macro:

• Carbohydrates are the primary energy source for your body and help it synthesize specific compounds, such as amino acids.
• Proteins are the building blocks of your body, as they play a crucial role in growing and repairing tissues.
• Fat acts as a storage system for your body’s energy while also protecting organs from external damage.

Disregarding macronutrients can have several side effects on your body. For example, a low protein intake is associated with delayed growth, impaired immunity, and a lack of energy.

To create a low-carb, low-fat diet, you’ll need to plan your meals so that your nutritional balance is composed of less than 30% fat and 26% carbohydrates. This would lead to it being made up of at least 44% protein — much more than the recommended 22% to 25%.

Very few studies investigate the side effects of consuming more than 40% of protein, as it’s practically impossible for the western diet to provide so much. Even when going for the “extreme” cases, it’s hard to find diets that go over this limit. For example, the Alaskan Inuit traditional diet is considered one of the most protein-dense eating plans — and it only goes up to 33%.

Experts suggest, however, that high protein intakes could lead to the following side effects:

• Upper digestive tract cancer
• Kidney cancer
• Damage to bone health
• Gastrointestinal disturbances

More research is needed to fully confirm the actual limits of human nutritional balance, but in the meantime, you should only perform a low-carb, low-fat diet under the close supervision of a doctor.

The medical side effects aren’t the only concerns surrounding a low-carb, low-fat eating plan. Such a diet could be tough to follow due to the restrictions it imposes. 

Here are some possible problems that could arise when you are attempting a low-carb, low-fat diet:

Lack of variety

Naturally, there are very few foods that contain the nutritional balance that would be required for a low-carb, low-fat diet plan. This can make the diet hard to follow, as you’d need considerable discipline to strictly use protein-dense foods.

Difficult to sustain

Similarly, a low-carb, low-fat eating plan would probably be very challenging to sustain in the long term. The lack of variety, the potentially expensive ingredients, the lack of confirmed benefits, and the possible side effects make this diet prone to desertion. This could lead to what is known as the “dieting cycle” — a constant looping between strict dieting and giving in to temptation with guilt.

Research suggests that low-carb diets may be more effective for weight loss compared to low-fat diets. Low-carb diets, such as the ketogenic diet, can lead to rapid weight loss in the first year, although they become less effective afterward. 

Meanwhile, combining a low-carb, low-fat diet may not be a wise option due to the potential for nutrient imbalances and the lack of research supporting this approach.

If you’re unsure about which diet is right for you, check with a doctor or licensed dietitian. A trained professional can give you precise instructions and take into account your health history and preferences.