The Basics

Claire Tunnell

Defining Meal Replacement and Protein Shakes

There are countless brands of meal replacement and protein shakes sitting on store shelves with each offering something different. As of January 2014, The U.S. Food and Drug Administration prepared a Guidance for Industry: Distinguishing Liquid Dietary Substances from Beverages due to the increase of products and popularity of protein and meal replacement shakes. Key factors in distinguishing a liquid dietary substance include the marketing of the product, the composition of the product, and recommendations for use and daily intake. Marketing a beverage as a liquid dietary substance must follow a set of regulations that include a prohibition on misleading labeling, health claims, nutrient content claims, and functional claims. If a beverage is marketed as a dietary supplement, it must follow given regulations with substances intentionally added, dietary ingredients added, and other non-dietary substances that are added. 

Currently, there is no clear definition of meal replacement through FDA guidelines. However, the guidelines for liquid dietary substances provide a point from which companies and consumers can make decisions. Leslie T. Krasny, who specializes in food and drug law, describes meal replacement products as "...200 to 250 calories per serving, are fortified with more than 20 vitamins and minerals at 'good' or 'excellence source' levels and often bear nutrient content claims..." in her article "Meal Replacements - Convenience or Compromise?"  Despite not having a clear definition, protein and meal replacement shakes have been consistently popular for years. From Slimfast to Muscle Milk to Soylent, protein and meal replacement shakes are a strong running fad diet. 

As a Long-Lasting Fad Diet   

We've all seen commercials on television advertising weight loss shakes that are usually accompanied by pictures of before and after photos of smiling people. Meal replacement shakes are marketed with the intention of promising weight loss, and in the small unmentioned text of the commercials, accompany drinking the shake with regular exercise and diet. Protein shakes are popular in gym culture. Casey Johnston's article, "How Protein Conquered America," illustrates how the popularity of the protein shake has grown in food culture. Protein and meal replacement shakes have been trending as a fad diet for years. While relying on these shakes for most of your meals is not the best diet route, they can still be utilized. Being mindful of what we're consuming through protein and meal replacement shakes is the first step in effectively using them.

The Importance of Checking the Nutritional Facts

Claire Tunnell

The Nutrition Facts, a label that provides detailed information about a food's nutrient content, is something all too familiar that we encounter every day. While checking the label is something we should practice frequently with anything we buy or consume, it is especially important to check on protein and meal replacement shakes. Most of these shakes are marketed along with the idea of being healthy, however, some are far from it. The nutrition facts label is like a roadmap we can follow to ensure that we're reaching our desired destination. While all the vitamins and minerals listed on the label might be the most interesting, I always look out for a few key components when choosing a protein shake: 

1. Calories: At the very top of the label is the calorie content. Some shakes have as little as 150 calories while other can have close to 300 calories. Calories are a measured unit of energy that illustrate the amount of energy that can be gained by consuming something. Everyone's daily caloric need is unique. Factors such as sex, height, weight, and activity level can all influence how many calories we need to consume. 

2. Fat: Fat is not the enemy. Our bodies need healthy fats to function. On top of that, fat is satiating and allows us to feel full. However, when considering fat in processed foods like protein shakes, we have to be cautious. There are multiple kinds of fats, the three primary kinds being saturated fat, unsaturated fat, and trans fat.

First, saturated fat is a type of fat that is generally found in animal products like meat and dairy as well as plant oils. It is known for raising LDL cholesterol, also known as the "bad" cholesterol. The American Heart Association recommends that 5%-6% of daily calories come from saturated fat. 

Second, unsaturated fat is mostly liquid at room temperature and is found in plants and oils. Examples of this include avocados and olive oil. The two types of unsaturated fat are monounsaturated and polyunsaturated fat. Monounsaturated fats can reduce LDL cholesterol in the blood and are an important part of our daily diet. Polyunsaturated fats are similar to monounsaturated fats in that they help reduce bad cholesterol. Polyunsaturated fats can also be found in food like salmon an provide us with omega-3 fatty acids which the body cannot produce on its own

Third, trans fat is a type of fat that is primarily processed through a process called hydrogenation. This process adds hydrogen to liquid vegetable oils to make them solid. Trans fats are used in producing products because they are cheap and provide a better taste. Similar to saturated fat, trans fat raises LDL cholesterol and lowers "good" HDL cholesterol. While trans fat can be found in many processed foods, there are some available with little to no trans fat. It is best to find a drink or powder with no trans fats. 

3. Sodium: Sodium, otherwise known as salt, is found in virtually every processed food. The recommended daily value for sodium is 2,300 milligrams. Two thousand and three hundred milligrams seems like a large amount to consume, but salt is present in almost every food we consume. It is found primarily in processed foods like bread or pre-packaged products. The American Heart Association provides a list of sources and ingredients where sodium is found. Currently, the Office of Disease Prevention and Health Promotion reports that the average sodium intake for men is 4,240 mg and 2,980 mg for women. While our bodies need sodium to function, we still have to mindful of the amount we are consuming through processed foods like protein shakes. It is important to look for shakes or powders with low sodium contents as we are probably consuming enough sodium in other foods throughout the day. As my personal preference, I generally look for shakes with less than 250-300 mg of sodium.  

4. Sugar: Similar to sodium, sugar is found in most processed and pre-packaged foods. The Office of Disease Prevention and Health Promotion reports that more than 13% of our daily calories come from added sugars and suggests that only 10% of our daily calories should come from added sugars. The American Heart Association recommends that only 100 calories come from added sugars for women and 150 calories for men. While it is easy to spot sugar on a nutrition facts label, it can also go by many other names in the ingredients list. These names are typically chemical sounding and are easy to gloss over. Here is a list of other names for sugar provided by Generally, names ending in -ose like dextrose or glucose are sugars. 

An important note about the nutrition facts label: While some categories can be listed as 0 grams, it does not mean that the nutrient is completely absent from the product. Labels can have 0 grams listed even when there are trace amounts or less than 0.5 grams of the nutrient present. This is significant when considering the amount of trans fat, sugar, or other nutrients you want to avoid. Here is an FDA nutrition labeling inspection guide. 

Categorizing Protein and Meal Replacement Shakes

Claire Tunnell

Protein Shakes

Protein is an important nutrient that is found in many places in the body. Its primary function includes building and repairing cells. Once digested it is broken down into amino acids, which are another essential nutrient. Protein is primarily found in foods like meats, dairy, and nuts. Protein shakes are advertised as just that - protein. Typically, the recommended daily allowance of protein is 0.8 grams per kilogram of body weight. A protein drink or powder generally has in between 20 and 40 grams of protein, which is close to half and more than half the average recommended daily allowance. Most brands boast a large amount of protein included in the powder or drink. Two popular protein powders are whey and casein. Whey protein is found in dairy foods and is a byproduct of cheese-making. Casein protein is a primary protein from dairy milk. While we need a certain amount of protein each day, there is such a thing as too much protein. Protein toxicity (the consumption of an excess amount of a nutrient), can pose stress on the kidneys and cardiovascular system. The Harvard School of Public Health explains that protein quality over quantity is what counts when considering health benefits from high protein diets. In this case, protein shakes are a good source of protein if needed but cannot compare to whole foods like nonprocessed meats and chicken. 

Meal Replacement Shakes

The infamous meal replacement shake has plagued television commercials for decades. Advertised as "satisfying cravings," the meal replacement shake has always been a sketchy contender in the fluctuating world of fad diets. Taking a popular brand of meal replacement shake, Slimfast, their generic meal replacement shake only offers 180 calories per serving along with a long varied list of vitamins and minerals. Most meal replacement shakes follow this trend of 100-200 calories and offering a wide variety of vitamins and minerals. The recommended daily allowance for these vitamins and minerals is just as varied and intricate. Here is a table for the RDA of vitamins, and here is a table for the RDA of minerals. As an example, the Slimfast shake offers a 110% daily value for vitamin C and 25% daily value for vitamin K. Despite all the vitamins and minerals, meal replacement shakes may not be the best option for, for a lack of better words, replacing a meal. More on this later.  

Plant Based Shakes

Although protein dense foods include meat, not all protein has to come from animal products! Protein can be found in plants, legumes, and even grains. Some notable sources include lentils, almonds, and spinach. Most brands of plant-based shakes offer the same benefits as protein and meal replacement shakes. Most include large amounts of protein and varied vitamins and minerals. However, the key difference is that most of the ingredients used in protein shakes are easily understood, and are of course plants. Simpler and fewer ingredients are always better. For example, a few ingredients from the Vega One All-in-One Shake powder include pea protein, flaxseed, and organic kale. Another example, the Orgain Protein Plant-Based Protein Shake has even fewer ingredients and advertises 0 grams of sugar. But one issue with this shake is a few sweeteners in the ingredients list: organic stevia and organic acacia gum. As stated before, sugar can go by many different names. Sweeteners are sometimes needed to make the powders and shakes palatable and don't mark the product as bad or unhealthy. But, even vegan and plant-based processed foods cannot bypass a good nutrition facts check. 

How to Choose and Incorporate Shakes into Your Diet

Shakes and powders can't replace the benefits of a wholesome meal, but they can still be used. As they are advertised, protein and meal replacement shakes are meant to serve as meal replacements or pre and post workout food. But, they can be utilized in ways other than dieting. Since each individual has their own unique lifestyle and tastes, choosing a shake or powder is just as unique. We all want different gains from our food so we have to find the options that are best for us. Shakes and powders should be viewed as a tool for our personal choices and needs rather than a strict diet. Personally, I use protein shakes as a source of caloric intake when I feel nauseous or not hungry at all, but know I need to eat something in order give my body the calories it needs to function. Additionally, we do not have to rely on processed shakes. If you have the time and resources, homemade shakes can be even more beneficial than processed shakes. Using whole and fresh ingredients in homemade shakes can help us avoid the negatives aspects of processed shakes and powders. Here are 4 Cheap & Easy Homemade Protein Shake Recipes

The Positives and Negatives

Claire Tunnell


It's easy to find negative aspects about anything, but meal replacement shakes and protein shakes are good for a few uses. Shakes and powders provide a light and easy way of consuming calories. If short on time or feeling sick, they can be consumed with virtually no preparation or effort. The provided calories can also be consumed before exercising to provide the body with something to burn and utilize. They also offer a wide range of vitamins and minerals if your regular diet is lacking in good sources. 


First and foremost, these shakes and powders are processed. While consuming processed foods is not the end of the world, we can always try to avoid these foods and their not so great parts like trans fat and excess sodium. 

Secondly, although all the shiny vitamins and minerals on the nutrition facts label appear helpful, most vitamins and minerals that we need can come from a well-balanced diet. Harvard Health Publishing explains that a diet rich in fruits, vegetables, and whole grains, offers vitamins and minerals that will meet the body's needs. While this is true, our nutritional needs are all different. We may need help gaining extra intake of a specific vitamin or mineral through supplements. 

Lastly, meal replacement and protein shakes don't offer the benefits of an actual meal. Katherine Zeratsky, R.D., L.D., writes that "Replacing meals with protein shakes may help you reduce your daily calories, which can help you lose weight. But eventually you will need to start eating solid food again, which may cause excess weight to return if you don't choose wisely." As I mentioned before, everyone has a unique daily caloric need depending on their weight and lifestyle. Expending more calories than consumed is what leads to weight loss, however, depriving yourself of needed calories can have the opposite effect. Dr. Joy Dubost RD, CSSD, explains how yo-yo dieting can have negative effects on metabolism and weight. If someone is consuming a significantly lesser amount of calories than they need, their metabolism will naturally slow to accompany that. Then when resuming their regular caloric intake, their metabolism will still be working for a smaller caloric intake. Dubost also explains that regularly depriving oneself of food can lead to future problems like blood pressure and diabetes. 

Overall, meal replacement and protein shakes, like any other food, have positive and negative aspects. Despite this, they can still be utilized to our unique needs. Processed shakes and powders can be effectively used as tools for our unique wants and needs. All it takes is awareness and mindfulness of what we're consuming and how our bodies can use it.