Losing weight and maintaining a healthy lifestyle can be a challenging journey. Many individuals seek effective strategies to support their weight loss goals, and metabolic weight loss drinks have emerged as a popular option. This article delves into the science behind these drinks, explores their potential benefits, and examines real-world experiences to provide a comprehensive review.
Understanding Metabolic Weight Loss
Metabolic weight loss focuses on enhancing the body's natural ability to burn calories and fat. This approach often involves dietary changes, exercise, and, in some cases, the use of supplements or specialized programs. Metabolic weight loss drinks are designed to complement these efforts by boosting metabolism, reducing appetite, and promoting fat oxidation.
The Science Behind Protein and Weight Loss
Protein is a crucial nutrient for weight loss. Consuming more protein can help you feel full longer, build lean muscle, and support your metabolism. Different types of protein powders contain distinct nutrients, each with its own benefits.
Protein's Role in Satiety and Appetite Control
Protein has been shown to help decrease hunger and appetite. One key reason is that protein generally helps you feel full for longer, partly due to the release of fullness hormones GLP-1 and PYY. Studies also show that higher protein intake may result in less hunger throughout the day. A 2015 study indicated that a high-protein breakfast helped older women consume up to 135 fewer calories later in the day, compared with a low-protein breakfast or skipping breakfast.
A 2016 meta-analysis of five studies also connected high protein intake and increased fullness. However, review authors caution that factors like body weight, eating behavior, and other health issues all play a role in the sensations of fullness. Furthermore, a 2020 review reports that ingesting more than 35 grams (g) of protein at once appears most effective for effects like less hunger, a reduced desire to eat, and greater feelings of fullness.
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Protein and Muscle Building
A high protein diet, especially when combined with strength training, can help build muscle. Because muscle aids metabolism and energy production, building muscle is a great way to keep your metabolism healthy. This is especially true if you follow a calorie-restricted diet to lose weight. Extreme calorie restriction may result in muscle loss and fat loss. This loss of lean muscle may slow your metabolism, making it easier to regain weight once you stop the restrictive diet. Conversely, eating sufficient amounts of protein, combined with strength training, may help prevent this muscle loss and resulting metabolic slowdown.
A 13-week study in older adults with obesity found that those who consumed an extra 20 g of protein weekly (in the form of a shake) gained 2.8 pounds (lb), or 1.3 kilograms (kg), more muscle mass than those who ate less protein. Plus, in a 6-week study, participants followed either a low or high protein diet, which included shakes. Each diet was calorie-restricted. Notably, participants following the higher protein plan gained 2.4 lb (1.1 kg) more muscle and lost 2.9 lb (1.3 kg) more fat.
Protein and Thermic Effect
Your body also uses more energy to digest protein than it does fat or carbs, which means your body burns more calories in the process. This effect, called the thermic effect of protein, may provide a slight metabolism boost.
Protein Shakes and Weight Loss: Studies and Reviews
Although few studies use protein shakes specifically, researchers generally agree that high protein diets are an effective way to lose weight and body fat. A 14-week study gave women with overweight or obesity a resistance exercise program alongside a high carb or high protein, calorie-restricted diet. Those in the high protein group lost 1.7 times more body fat than those in the high carb group. In a 12-week study, women with a moderate weight but high body fat percentage followed either a high or standard protein diet. Those on the high protein diet lost an additional 3 lb (1.4 kg) of body fat and around 1 inch (2.2 centimeters) in waist circumference. The participants in the high protein group also retained significantly more muscle mass than those on the standard protein diet. A 2020 review further suggests you can minimize weight regain by following a high protein diet in the first 3-12 months after losing weight. However, long-term studies must confirm whether this effect lasts beyond the first year. Still, a small 2017 study found that when participants with excess weight drank low sugar protein shakes as part of a diet program, their weight loss improved.
Protein’s effect on metabolism, appetite, and muscle mass may also help prevent regaining weight once you’ve lost it. One 2015 review suggests that higher protein intakes of 25-30 g per meal improve both weight loss and weight management. However, researchers caution that full adherence to a high protein diet, plus other lifestyle factors, is usually necessary. Similarly, studies suggest that high protein diets result in less short-term weight regain after you lose significant amounts of weight. All the same, more studies are needed.
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Types of Protein Powders
Protein shakes are made by mixing protein powder with water or another liquid, plus optional other ingredients. Although most people don’t need protein shakes to meet daily protein requirements, protein shakes can be convenient if you have limited access to high protein foods or experience trouble meeting your needs through food alone.
You can buy protein powder and mix it yourself or purchase premade liquid shakes.
Whey Protein
Whey protein is quickly absorbed, dairy-based, and contains all nine essential amino acids.
Casein Protein
Casein protein is slowly absorbed, dairy-based, and provides all essential amino acids.
Soy Protein
Soy protein is plant-based and offers all essential amino acids, plus soy isoflavones that may provide some health benefits.
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Hemp Protein
Hemp protein is plant-based, contains all essential amino acids, rich in omega-3 and omega-6 fatty acids, and has a high arginine content.
Rice Protein
Rice protein is plant-based but lower in the essential amino acid lysine.
Pea Protein
Pea protein is plant-based and less allergenic alternative to soy and whey protein, but lower in the essential amino acids cysteine and methionine.
Certain protein powders and drinks contain a mix of protein types. For example, many plant-based brands combine types to diversify the amino acid profile. Some dairy-based protein powders combine whey and casein to provide immediate and longer lasting effects on muscle synthesis.
Choosing the Right Protein for Your Needs
Different types of protein may affect your body in distinct ways. For instance, whey is typically absorbed more quickly than casein. This makes it optimal for promoting muscle protein synthesis after exercise. It may also help you feel less hungry in the short term. While some small studies have shown whey protein to be more effective for weight loss than soy and other plant-based proteins, others show no real difference. As such, individual lifestyle factors may be more important than the type of protein regarding weight loss or other desired outcomes.
One key factor to consider is the quality of protein you purchase. Whey, casein, and soy are considered complete proteins. This means they contain sufficient amounts of all the essential amino acids your body needs. All the same, these three may induce an allergic reaction in some people. Rice and pea protein are often considered less allergenic. However, rice protein is low in the essential amino acid lysine. Pea protein is low in the essential amino acids cysteine and methionine. Hemp protein is also considered less allergenic. Furthermore, it contains sufficient levels of all essential amino acids. As such, it can be considered a complete source of protein.
As long as you regularly consume a variety of protein sources, opting for incomplete proteins in your protein shake is unlikely to be a problem. That said, it’s always best to talk with a doctor or registered dietitian before adding new supplements to your diet.
Whole Food Alternatives for Protein Shakes
Protein powders aren’t the only way to add additional protein to your shakes. Here are a few whole foods you can use in place of protein powder:
- Greek or plant-based yogurt: Greek yogurt is naturally rich in protein, as are plant-based alternatives made from soy. Each provides around 6-10 g of complete protein per 3.5 ounces (oz), or 100 g.
- Nuts and seeds: Most nuts and seeds pack around 5-7 g of protein per 1 oz (28 g). Combine with soy or hemp milk for a complete source of plant-based protein.
- Spirulina: This blue-green algae offers around 8 g of complete protein per 2 tablespoons (14 g). This serving also covers 95% of the Daily Value (DV) for copper and 22% of the DV for iron.
- Tofu: This popular soy food contains around 5-13 g of complete protein per 3.5 oz (100 g), depending on the variety. It has a naturally mild flavor, so you can blend it with frozen fruit and liquid to yield a protein-rich shake.
- Puffed quinoa: This pseudocereal provides around 10 g of complete protein per 2.5 oz (70 g). Expect it to thicken and add a slightly nutty flavor to your shake.
- Oats: This grain offers around 5 g of protein per 1.5 oz (40 g). Combine with cow’s milk or hemp milk to get a complete source of protein.
These protein-rich ingredients are an easy addition to homemade shakes. Simply combine them with your choice of dairy or plant-based milk, fruit, and leafy greens for a nutrient-rich, whole-food alternative to protein powder-based shakes.
Safety and Considerations
The Food and Drug Administration (FDA) doesn’t typically review supplements for safety and effectiveness before they hit the shelves. Thus, it’s important to research the ingredients in your protein powder and the brand’s trustworthiness. When possible, choose a protein that has undergone third-party testing. Additionally, suggestions for serving sizes also vary by brand. Make sure to check nutrient labels to be sure you’re getting the amount of protein you desire.
If you’re lactose intolerant, drinking protein shakes made with whey or casein may cause side effects, such as:
- bloating
- cramps
- gas
- diarrhea
You can avoid these symptoms by switching to protein powders not derived from dairy, such as those made with protein from eggs, peas, soy, or hemp.
While most research suggests high protein diets are safe, people with underlying kidney issues may need to avoid them. If you have kidney complications, talk with your doctor before increasing your protein intake.
Most adults can easily get enough protein through food sources without drinking protein shakes. That said, protein shakes can be a delicious way to add extra protein to your diet. If you’re trying to lose or manage weight, extra protein from shakes may help you feel less hungry.
Metabolic Research Center (MRC) and Its Offerings
Metabolic Research Center (MRC) is one such provider that has garnered attention for its weight loss programs and products, including protein drinks and bars. MRC aims to assist individuals in achieving their weight loss goals through personalized approaches and a range of supportive products.
Testimonials and Reviews of MRC
Many individuals have shared their positive experiences with MRC, highlighting the effectiveness of the program and the support provided by the staff. For example, Megan reported losing 40 lbs since starting the program in April, praising the personal approach and the protein drinks and bars. She particularly enjoyed the strawberry kiwi and peach mango drinks, as well as the key lime pie and peanut protein bars.
Elizabeth expressed feeling confident in changing her relationship with food, thanks to the encouraging coaches and the options provided. Alisa hailed MRC as the best place for weight loss, with an amazing staff at the Pueblo location. Bridgett commended the super-friendly and helpful staff, especially Katlynn, a health coach in the Pueblo office.
Joan shared her struggle with weight gain over the past five years and how MRC helped her lose 20 pounds, alleviating her foot and knee pain. She appreciated the knowledgeable and encouraging staff, particularly Ashley and Katlynn, who provided strategies to navigate tough times. Linda praised the caring and knowledgeable team at the Pueblo MRC, emphasizing the combination of products, support, and accountability.
NJ shared a remarkable journey, losing 45 lbs in about 8 months with MRC's medical programs, including Tirzepatide. NJ successfully discontinued diabetes medications and maintained the weight loss for a year and a half, attributing the success to the great coaches and the program's lasting impact.
MRC Products: Protein Drinks and Bars
MRC offers a variety of protein drinks and bars designed to support weight loss and provide convenient, nutritious options. These products are formulated to be high in protein, which aids in satiety and muscle preservation during weight loss. The flavors and formulations are created to be appealing and satisfying, making it easier for individuals to adhere to their weight loss plans.
High-Protein, Fiber Nutritional Supplement Shakes
A study published in Cureus in April 2025 by Manohar KN et al. highlights the benefits of high-protein, fiber (HPF) nutritional supplement shakes. The study involved 206 healthy overweight and obese adults, who were randomly assigned to either an HPF group (17 g protein, 6 g fiber) or a low-protein, fiber (LPF) group (1 g protein, 3 g fiber). Participants followed an energy-restricted diet (500 kcal/d less than energy needs) and consumed a shake 30 minutes before breakfast and lunch for 12 weeks.
The results showed that while both groups experienced weight loss, the HPF group had significantly greater weight loss at day 84 compared to the LPF group (-3.3 kg vs. -1.8 kg, P < 0.05). Although percentage body fat decreased in both groups, there were no significant differences between the groups. The study concluded that a multi-ingredient HPF nutritional supplement shake, consumed as a preload before breakfast and lunch, positively influenced weight management and metabolic outcomes in overweight adults compared with an LPF placebo. These findings suggest that specific nutrient factors, such as protein, fiber, and bioactive content, play a crucial role in the success of a weight-loss regimen.
The Role of Fiber
Fiber plays an important role in weight management by promoting satiety and improving metabolic outcomes. A recent systematic review and meta-analysis reported greater reductions in BMI, body weight, and body fat, as well as improvements in cardiometabolic outcomes, with the consumption of soluble fiber compared with placebo. Another review reported that an average of an additional 14 g fiber/d for >2 d is associated with a 10% decrease in energy intake and subsequent weight loss.
Combining Protein and Fiber
Recent research has focused on the benefits of combining moderate amounts of protein and fiber. A study by Douglas et al. (17) compared the consumption of a single high-protein (34 g)/low-fiber (1 g) meal with that of a more moderate-protein (14 g)/fiber (5 g) meal in healthy adults. Similar appetite and satiety responses, as well as similar daily food intakes, were observed when replacing some protein (∼20 g) with fiber (+4 g).
Bonnema et al. (19) examined the effects of consuming breakfasts varying in protein and fiber on satiety, glycemic control, and food intake. The more moderate protein (20 g)/fiber (7 g) meal led to similar reductions in postprandial glucose and subsequent food intake compared with the high-protein (30 g)/low-fiber (1 g) breakfast, and both reduced glycemic response and food intake compared with a lower-protein (10 g)/low-fiber (1 g) breakfast (19).
Clinical Trial: HPF vs. LPF Supplement Shakes
A 12-week randomized, double-blind, placebo-controlled trial was conducted to determine if greater weight loss and changes in body composition could be achieved with twice-daily consumption of a protein and fiber-based multi-ingredient nutritional supplement shake (HPF) compared with an isocaloric LPF in adults with overweight and obesity.
Study Design and Methods
Two hundred and six healthy adults with a BMI of 27.0-35.0 were recruited and randomly assigned to either the HPF or LPF group. The HPF group consumed a commercially available dietary supplement shake containing 17 g protein and 6 g fiber, while the LPF group consumed a maltodextrin-based placebo supplement containing 1 g protein and 3 g fiber. Both groups followed an energy-restricted diet (500 kcal/d deficit) and were advised on guidelines for physical activity.
Outcomes were measured on days 0, 28, 56, and 84, including body weight, heart rate, blood pressure, waist and hip circumference, and venous blood draw. Body composition was assessed using DXA scans.
Results
The study found that participants in the HPF intervention group experienced greater weight loss compared to those in the LPF group. The HPF supplement shake, containing a blend of whey and pea protein, fruit-, vegetable-, and plant-derived powders, vitamins, minerals, prebiotics, and probiotics, contributed to improved weight management and metabolic outcomes.
Practical Tips for Incorporating Metabolic Weight Loss Drinks
- Choose the Right Protein Powder: Select a protein powder that aligns with your dietary preferences and needs. Consider whey, casein, soy, hemp, pea, or rice protein based on your individual requirements and potential allergies.
- Combine with Fiber: Enhance the satiety and metabolic benefits of your protein shake by adding fiber-rich ingredients such as flaxseed, chia seeds, oats, or psyllium husk.
- Add Healthy Fats: Incorporate sources of healthy fats like nuts, seeds, or avocado to promote fullness and support overall health.
- Use Whole Food Ingredients: Opt for whole food ingredients like Greek yogurt, fruits, and vegetables to boost the nutrient content of your shakes.
- Stay Hydrated: Drink plenty of water throughout the day to support metabolic processes and overall well-being.
- Consult a Professional: Seek guidance from a registered dietitian or healthcare provider to create a personalized weight loss plan that incorporates metabolic weight loss drinks effectively.