weight loss · Jun 03, 2025

Should You Cut Carbs, Fats, or Protein to Lose Weight?

By Sarah Jayawardene, MS

Is a high-fat or high-protein diet better for health? Will low-carb or low-fat meals make you lose weight faster? With so many conflicting dietary trends, deciding whether to cut carbs, fats, or proteins for weight loss can feel overwhelming.

When it comes to weight loss, there’s no one-size-fits-all answer. Your metabolism, lifestyle, and personal preferences all play a role in determining the best strategy for losing weight and keeping it off. Research suggests that a balanced ratio of carbs, protein, and fat — paired with healthy food choices — promotes sustainable weight loss results. By understanding how each macronutrient affects your body, you can make informed decisions to achieve your goals. Remember: the most effective diet plan is the one that you’ll stick to.

How Do Macronutrients Affect Weight Loss?

Not all calories are created equal. Protein, fat, and carbohydrates each play a unique role in how your body burns energy, manages hunger, and stores fat. Here’s how each one can impact your weight loss progress.

Protein

Muscle mass: Losing weight doesn’t always mean losing fat — in fact, many people lose both muscle and fat during the process. This matters because muscle mass is more metabolically active than fat mass, meaning it helps you burn more calories even at rest [1]. A cornerstone of the weight loss process is getting enough protein in your diet, due to its role in muscle preservation. If you don’t get enough protein in your diet (or are taking weight loss medications like Ozempic), muscle loss can lead to a slower metabolism and make it harder to lose weight. Prioritizing healthy sources of protein in your diet helps preserve lean muscle, keeping your metabolism more resilient even as the number on the scale drops. If you’re taking weight loss supplements, ensure you’re taking one that is formulated with ingredients that support fat loss without muscle loss. Motus, Tonum’s weight loss supplement, has been clinically studied to improve fat loss by 25% without muscle loss.
Thermogenic effect: Protein has a high thermic effect of food, meaning your body burns more calories digesting it as compared to carbs or fats [2]. Up to 20-30% of calories from protein are used in its digestion.
Blood sugar and satiety: Protein helps to regulate blood glucose levels, which leads to reduced cravings and stabilized energy levels. Protein is also the most satiating macronutrient, meaning higher protein intake leads to increased feelings of fullness and less overeating, which makes it easier to maintain a calorie deficit and lose weight without hunger pangs.

Fat

Hormones and cell function: While often misunderstood or antagonized, fats are an indispensable part of a healthy diet. They are essential for hormone production and regulation, including those that influence appetite, metabolism, and stress response. Fats also support the structure and function of every cell in the body, aid in the absorption of fat-soluble vitamins (A, D, E, and K), and help maintain healthy skin and brain function [3].
Satiety: Consuming healthy fats can help with feeling full, which helps prevent overeating while still providing sustained energy. Fats are also calorie-dense, so moderation is key, but cutting them out entirely can disrupt hormonal balance and actually lead to increased hunger.
Metabolic health: Healthy fats, like omega-3s found in fatty fish or nuts, play a significant role in supporting your metabolic health. They help regulate insulin sensitivity, which can improve how your body uses and stores energy (key factors in weight management). They also have anti-inflammatory properties that can help combat the inflammation associated with obesity and metabolic disorders, which can further aid weight loss [4].

Carbohydrates

Primary energy source: Carbohydrates are the body’s primary energy source — they are broken down into glucose, a molecule your body uses to produce ATP, the energy that powers your cells and all the chemical reactions that keep you alive. Carbohydrates are especially important for high-intensity activities like exercise (athletes need carbs) so it’s important not to cut them out entirely if you live an active lifestyle.
Blood sugar: Not all carbs are equal. While refined carbs and simple sugars can hinder weight loss by causing rapid blood sugar spikes that can lead to cravings and energy crashes, fiber-rich carbs provide steady energy and improve satiety. Reducing refined sugars and ensuring you get enough fiber in your diet via vegetables and whole grains can stabilize blood glucose and insulin levels, in turn supporting weight loss [5].

What Is the Ideal Macronutrient Ratio for Weight Loss?

There’s no universal macronutrient ratio for weight loss that works for everybody, but the Dietary Guidelines for Americans (2020–2025) provide a good starting point [6]:

Protein: 10–35% for people older than 18
Fats: 20–35% for people ages 4 and older
Carbohydrates: 45–65% for everyone

These ranges are flexible — they are general guidelines and don’t necessarily work for every individual. For example, low-carb diets may benefit people with sedentary lifestyles or insulin resistance, while athletes may thrive on higher carb intakes (50-65% of calories) to fuel their performance. On the other hand, high-protein diet plans (25-35% of calories) can help with weight loss for the majority of individuals due to its muscle-preserving and appetite-suppressing effects.

The bottom line? While research shows that weight loss is possible with many different types of diets, the key is to eat fewer calories than you are burning [7]. The ratio of macronutrients in your diet will affect how easy or difficult it is to maintain a calorie deficit and support your metabolism.

To find what works for you, experiment with small adjustments. Try slightly reducing daily carbs or increasing your protein intake. Track your energy levels, what cravings you have, and any weight changes to assess what the best macronutrient ratio is for you. This tactic provides a more balanced approach, rather than cutting any one macronutrient out completely, and can help you find the right balance for your body.

Make Sure You’re Getting Quality Macronutrients

The quality of your macronutrients matters as much as their amounts or the ratio you eat them in. Cutting calories without prioritizing nutrient-dense foods can lead to various nutrient deficiencies, increased cravings, and unstable blood glucose levels, which can all lead to weight gain [8].

Try to choose high-quality sources for your macronutrients:

Protein: Opt for lean meats (chicken, turkey), fish (salmon, mackerel), legumes (lentils, chickpeas), tofu, or Greek yogurt. These provide essential amino acids without excessive calories.
Fats: Choose olive oil, avocados, fatty fish, nuts, and seeds. Avoid trans fats and limit processed oils to support heart health and reduce inflammation.
Carbohydrates: Prioritize whole grains (quinoa, brown rice), vegetables (broccoli, spinach), fruits (berries, apples), and legumes. Ensure you’re eating a colorful array of vegetables (which are rich in anthocyanins and phytonutrients) and getting enough fiber. Minimize refined sugars and processed foods like white bread and sugary drinks.

Why Your Diet Should Be Personalized

Everyone’s metabolism is slightly different — your body processes macronutrients differently than others based on your genetics, body composition, lifestyle, and many other factors.

Athletes may need a higher carbohydrate intake to fuel intense workouts, while individuals who are more sedentary might benefit from reducing carbs intake to improve their insulin sensitivity. Some people thrive on low-carb, high-fat diets like keto, while others feel energized with evenly balanced ratios. Listening to your body — by monitoring energy, mood, and hunger levels — can help you to identify the best carb, protein, fat ratio for your individual weight loss journey.

Sustainability is the key to weight loss and weight maintenance. Restrictive diets that strictly limit or entirely eliminate macronutrients are hard to maintain and may lead to nutrient deficiencies or weight regain over time [9]. An effective diet is one that you can easily stick to long-term and is tailored to your preferences and health goals. Small adjustments, like swapping refined carbs for whole grains, can make a significant difference.

Supplement With Motus

While making adjustments to your diet and figuring out the best macronutrient ratio for your body, you can incorporate supplements like Motus to enhance your weight loss efforts.

Developed alongside Duke Health, Motus contains several science-backed nutraceutical compounds that work synergistically to support metabolic efficiency, promote healthy blood sugar levels, and improve fat loss without muscle loss. In fact, a study on mice found that Motus led to 25% more fat loss than untreated groups, without a loss of lean muscle mass.

Takeaways

Losing weight doesn’t require drastically cutting carbs, fats, or proteins — it’s about finding the macronutrient ratio that suits your body and your lifestyle.

Prioritize high-quality, nutrient-dense foods to stabilize your blood sugar, reduce cravings, and maintain your energy levels.
Protein is important for muscle preservation and feelings of satiety. Healthy fats and fiber-rich carbs support satiety.
Making small adjustments, tracking your progress, and considering supplements like Motus can all enhance your results.
Focus on balance and sustainability, you can achieve your weight loss goals while feeling empowered and energized on your health journey.

References

Sarah Jayawardene obtained her Master’s degree in Biochemical and Molecular Nutrition at Tufts University. She has a deep passion for nutrition science and health communication, with expertise in metabolism and metabolic diseases. As a supporter of integrative and functional medicine, Sarah strives to provide her readers with science-backed information that lends to improved health and wellness.

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