After long periods of resistance training, the time finally comes to shed the fat and reveal that hard-earned muscle. That said, losing weight and losing fat are not the same thing. Fat loss, without subsequent muscle loss, can be a significant challenge.

Protein is a beneficial part of any diet plan. For casual dieting, protein keeps you full longer, which reduces your appetite and curbs cravings. In addition, protein boosts your metabolism and allows your body to burn more calories at rest.

As part of a fat-loss plan, however, protein is vital. Not only does it provide the same benefits as traditional dieting, but it also preserves existing muscle tissue and helps with performance.

Protein shakes are an easy and convenient way to add more protein to your diet without an excess of calories, sugar, or fat.

What are Protein Shakes?

Protein shakes are made from a powder that’s mixed with water or other ingredients like milk, yogurt or dairy alternatives. There are also many types of commercially-available, pre-mixed protein shakes that come in a “ready to drink” form for added convenience.

Some common types of protein powder are:

Whey is the most common type of protein powder, but many people use plant-based protein powders to avoid animal products or gain additional nutrition benefits.

Protein powder comes in many flavors and can usually be combined with other foods, like milk, yogurt, fruit, nut butter, or seeds for added nutrients.

Protein as an Appetite-Suppressant

To diet effectively, your appetite must be in check. Protein is effective for controlling appetite in two ways.

bon appetit

The hormones GLP-1, PYY, and CCK all send signals to your brain to say you’ve eaten enough. Because protein makes you feel full and satisfied, it increases levels of these hormones. In addition, ghrelin, a hormone tied to feelings of hunger, is also reduced by adequate protein intake.

Combined, these two effects can keep you from feeling starved and deprived on your diet, as well as keeping you from reaching for unhealthy snacks and craving high-sugar or high-fat foods in between meals. The result is that you eat fewer calories over the course of the day.

Unlike full meals, protein shakes are able to provide a quick, on-the-go snack that keeps you on track in between meals.

Protein Boosts your Metabolism

High-protein diets and strength training build muscle. Your metabolism speeds up because muscle mass burns more calories than fat.

During a caloric deficit, muscle mass can become depleted. Combining a high-protein and continued strength training helps to preserve as much muscle mass as possible, which keeps your metabolism up.

Preserving muscle mass and metabolism is important for anyone dieting, but it’s a specific goal of those looking to lose fat and reveal muscle. Adequate protein levels ensure that your lean mass stays intact, despite a lower caloric intake.

In addition, protein increases your metabolism directly, since your body has to work harder to digest it. This is called the thermic effect of food. On average, 15-30% of calories from protein are burned during digestion, compared to 5-10% of calories from carbohydrates and 0-3% of calories from fat.

Protein Improves Body Composition

All fat is not created equal. Studies indicate that the distribution of your fat is a much better indicator of potential health problems than overall weight. A high concentration of abdominal fat is a precursor to many conditions, including heart disease, stroke, and diabetes.

strength training

Strength training can improve body composition on its own, which is why people tend to notice a difference in the fit of their clothing, even if the scale hasn’t budged. Protein is needed to maintain this muscle mass, but also directly leads to a loss of abdominal fat.

Protein Keeps the Weight Off

Protein’s effects on metabolism and weight loss are long-lasting. Not only is it preserving the existing muscle mass so that it can continue to grow, but it also keeps your metabolism high after dieting. This allows you to maintain your healthy weight.

Short-term, extreme diets tend to result in a rebound when the diet’s over, but the impact of protein on your appetite and cravings can also encourage better nutrition habits. A healthier approach to nutrition and dieting is far more sustainable in the long term, which decreases the likelihood of gaining the weight back.

Will Protein Make Me Bulk Up?

When it comes to building muscle, protein is only part of the equation. Muscle gains are made through “progressive overload,” which is gradually increasing the volume, intensity, and frequency of weight lifting to increase muscle mass significantly. It doesn’t happen without effort.

bodyweight training pull up

Protein is vital to building muscle, but it can’t create muscle without resistance. Women, in particular, are unlikely to gain a great deal of muscle without putting a great deal of work in, since their bodies aren’t designed for the same muscle gains as men.

Without extensive weight training, protein merely preserves the existing muscle tissue and helps build lean muscle mass, as well as keeping fat off.

Choosing a Protein Powder

While all protein sources will have similar benefits, they each have different effects on the body.

Whey is popular because of its fast absorption. This is an important factor for serious strength training since more active individuals require higher protein levels to maintain their muscle mass.

Casein is a slow-digesting protein, which makes it a good choice for in between meals and overnight protein needs. Casein is also very good for preventing muscle breakdown and preserving lean mass.

Plant-based protein, like soy, hemp, or rice, is a complete protein, but some may be low in certain essential amino acids. This is usually not an issue unless they’re being used as a sole source of protein. In addition, some plant-based protein powders have added sugars or other ingredients that may affect the overall calories and nutrition.

Meal Replacement Shakes vs. Protein Powder

The main difference between meal replacement shakes and protein powder is the nutrition profile.

meal replacement


Meal replacement shakes are typically higher in calories (200 to 500) and include a number of added vitamins, minerals, fiber, and small amounts of protein. They are designed to “replace” meals, so they offer nutrients that are more closely aligned with a full meal.

Protein powder is lower in calories (80 to 180), higher in protein, and have fewer vitamins and minerals. They are also much more versatile in their preparation since they are designed to be a supplement, rather than a full meal replacement.

Meal replacement shakes are generally geared more toward weight loss, rather than increasing protein intake, though they can be beneficial for individuals who struggle with portion control or cravings.

Bottom Line

Regardless of type, increasing your protein intake can help you reach your weight loss goals by increasing your metabolism, maintaining your muscle mass, and decreasing cravings and hunger pangs that can derail your diet.

For health and fitness that extends beyond a short-term goal, lifestyle changes need to happen. Nutrition that emphasizes a balanced diet of whole, unprocessed foods ensures overall health, weight loss, and well-being.

To get started on the path to wellness, visit our diet plans page for information.