Note: This post originally appeared as a guest post on ThePaleoMom.com. Shakes and smoothies are growing in popularity within the Paleo community. Protein shakes are all the rage among Crossfitters and other athletes that are concerned with post-workout nutrition, but also among busy professionals and parents, individuals with either weight loss or weight gain as a goal, pregnant and nursing women, those struggling with autoimmune disease, and the average person searching for optimal health. One of the most frequent questions that I receive in my work as a nutritional therapist is, “What kind of protein powder do you recommend?” The appeal of shakes and smoothies lies in their convenience and presumed fit with our modern, hectic lifestyles. It doesn’t take much time or preparation to throw together a shake or smoothie and drink it. The convenience factor aside, most of us have been subjected to the influence of heavy marketing efforts that have convinced us that not only do we need more protein in our diet, but the addition of a protein shake can do amazing things for us: gain muscle, lose fat, improve energy levels, reduce recovery time, become a better athlete, meet all of our daily nutritional requirements, and become healthier overall.
Despite these claims, protein powders are highly processed products and they are not a whole food. Protein powder can be derived from any food that contains protein. The most common types of protein powders include soy, whey, casein, complete milk (whey and casein), egg, rice, hemp, and pea protein. Many of these options obviously do not fit into the Paleo paradigm, but a few are touted as being more acceptable in the Paleo community, including whey and egg protein. With whey in particular, there are protein powder companies that advertise that the cows from which the whey comes from are grass-fed. Regardless of how humanely or sustainably-raised the source is, the process of making any type of protein into a powder usually utilizes extremely high temperatures that denature the protein in a way that can be harmful and can contribute to the formation of carcinogens (as opposed to the normal process of denaturing proteins that occurs during cooking or digestion).
In the United States, protein powders are considered to be a supplement by the Federal Drug Administration (FDA) and they are not subjected to the same labeling requirements or regulation as food. Many protein powders contain artificial sweeteners, preservatives, and a variety of undesirable ingredients and fillers that are listed on the label, but what may not be listed on the label can also be concerning. A Consumer’s Report investigation found unsafe levels of arsenic, lead, mercury, and cadmium in several popular protein powders. There have also been numerous reported cases of undisclosed steroids and stimulants found in protein powders.
Many people drink shakes or smoothies because they believe for one reason or another that they need to include more protein in their diet. In industrialized countries, protein deficiency is exceedingly rare. The evidence suggests that protein intake is homeostatically regulated by the body. In other words, if your body requires more protein, there are complex processes that occur that will lead you to crave and eat more protein. If your body needs less protein, you will be averse to it and you will naturally eat less protein. A good example of this is during pregnancy in which many women become noticeably averse to various types of proteins. There is some thought that protein aversions during pregnancy may be an attempt by the body to limit protein intake as too much protein could be harmful to the fetus. Because of the tightly controlled regulation of protein intake by the body, the vast majority of people do not need to supplement with protein in order to meet their daily requirements and achieve their health goals.
For those that are participating in Crossfit or other strenuous activities, post-workout nutrition certainly is important. However, there is absolutely nothing present in protein powder that cannot be obtained from real food. The goal of post-workout nutrition is to replenish glycogen stores and increase protein synthesis. Many athletes want to reduce recovery time, meet their muscle gain and/or weight loss goals, and enhance overall health. The healthiest way to do this is by eating real food! The composition of a post-workout meal may vary depending on your activity level and specific goals, but drinking your post-workout nutrition in the form of shakes and smoothies is not the best choice. Liquids require less digestion which leads to a rapid surge in blood sugar levels, instead of a slower and steadier blood sugar rise that occurs after eating a meal with protein, carbohydrates, and fat. This study found that whey protein has an insulin response that is 90% higher than the insulin response to white bread. Even though exercise increases insulin sensitivity, this type of drastic insulin response is not ideal.
Many people in the Paleo community drink smoothies without any protein powder added. Typically, these smoothies consist of green, leafy vegetables, fruit, and coconut or nut milk. Smoothies are often viewed as a healthy treat and an easy way to introduce more greens, such as spinach or kale, into the diet. However, the main problem with smoothies lies in their impact on blood sugar levels. In order to make these green smoothies taste palatable, most people add a hearty dose of fruit. Fruit does play a role as part of a nutrient-dense Paleo template, but too many natural fruit sugars is not necessarily a good thing. Just as with the liquid protein shakes, smoothies hit the blood circulation quickly and require a faster and more marked insulin response. Smoothies are also not as satiating as a balanced meal. Drinking a smoothie as a meal replacement can lead you to become hungry more quickly and cause you to over-consume. Also, when you choose to drink a smoothie in place of a meal, you are missing out on a variety of other nutrients that you could be including in your diet.
In general, it is never ideal to drink your calories! Protein powders are highly processed and they cannot provide any nutrition that you cannot obtain through real food. Despite the common misconception, most people do not need to consume more protein. Both protein shakes and smoothies do have a convenience factor, but it may come at a steep cost of drastic blood sugar swings. When in doubt, it is always best to rely on eating real food to meet your needs.
What are your thoughts on shakes and smoothies? Do you think they belong in a nutrient-dense Paleo template?