Protein is one of the three macronutrients, according to Verywell Fit. High-protein diets tend to rise and fall in popularity, with examples like the keto diet, Atkins, and Southbeach. Protein’s impressive reputation is largely due to extreme marketing efforts. Many trending diets completely eliminate the other two macronutrients. However, protein, carbs, and fat are all equally essential for overall health. As Healthline explains, you should aim to consume 0.36 grams of protein per pound of body weight. Your protein needs will vary depending on your activity level, muscle mass, and sex.
With this foundational knowledge, we became curious. What, we wondered, would happen if someone drank only protein shakes every day? We searched the internet for scientific data, firsthand experiences, and nutritionists’ insights and compiled extensive information on the effects of over-consuming protein. Whether you’re a fitness enthusiast, a cardio lover, or simply someone who enjoys protein shakes, read on to learn what relying solely on these smoothie-like drinks might do to your body.
You’ll certainly get enough protein
Obviously, if you exclusively consume protein shakes, you’ll meet your recommended daily allowance (RDA) of protein. This is beneficial, as protein helps repair small muscle tears, a positive outcome of weightlifting, according to the San Francisco Chronicle. Your body requires protein to fix workout-induced damage. Highly active individuals might need up to 1.6 grams of protein per kilogram of body weight, as noted by Medical News Today.
To determine your protein needs, first calculate your weight in kilograms. One pound equals 0.45 kilograms. For instance, a 120-pound fitness enthusiast weighs 54.43 kilograms. If she aims for 1.6 grams of protein per kilogram, she’d multiply those numbers, resulting in a daily minimum of 87.01 grams of protein.
Whey protein powder typically contains around 30 grams of protein per scoop. Even with high needs, three scoops could satisfy her daily protein requirement. Many plant-based protein powders offer 15 to 20 grams per scoop, but solely relying on protein shakes would likely provide more protein than your body can use, according to the San Francisco Chronicle.
Your muscles may repair faster
A complete protein consists of all 20 amino acids, which are categorized into essential and nonessential groups (via Healthline). Your body can’t produce the nine essential amino acids and need to be consumed for a complete protein structure. Protein is broken down into amino acids, each performing specific tasks in the body. Fun fact: Every cell in your body contains some form of protein (via Medline Plus).
When you work out, you’re essentially damaging muscle fibers. In response, they grow back stronger, leading to muscular hypertrophy, as explained by Healthline. With ample protein, your muscles have the necessary tools to repair optimally (via HuffPost).
However, relying only on protein shakes may deprive your body of micronutrients, abundant in colorful, whole foods. Skipping these nutrients could hinder full recovery (via Healthline).
You might not feel quite so hungry
According to a study published in the British Journal of Nutrition, it’s not necessarily the lack of carbs in a low-carb diet that leads to weight loss. The study noted, “The success of the so-called ‘low carb’ diet that is usually high in protein can be attributed to the relatively high-protein content per se and not to the relatively lower carbohydrate content.”
High-protein diets can promote prolonged fullness compared to carbs alone. High-protein breakfasts have been shown to reduce hunger throughout the day, per Harvard Health. Consumed in moderation, protein shakes can enhance satiety. Defined as “the quality or state of being fed or gratified to or beyond capacity” by Merriam Webster, satiety means less hunger. However, some protein powders contain sugar or additives that could harm your health (via Livestrong). Remember to consume more than just protein shakes.
You might lose weight
A healthy mix of all three macronutrients, with protein as a priority, can lead to satiety, as noted in a 2016 study in Advances in Nutrition. Feeling less hungry due to a satisfying breakfast may deter you from snacking on pastries at work. From this perspective, daily protein shakes might aid weight loss.
Many fad diets incorporate protein shakes, with simple logic: replacing a 500-calorie meal with 100 to 200 liquid calories creates a calorie deficit. Maintaining this deficit over time forces your body to shed extra weight (via NASM).
However, experts at the San Francisco Chronicle warn against overconsumption of protein shakes. If they’re your main sustenance, you could face nutritional deficiencies. Moreover, relying solely on protein shakes might lead to unsustainable dieting, and returning to a balanced diet could result in weight gain (per Verywell Fit).
You could gain weight
Consuming only protein shakes might not result in the weight loss you expect (via San Francisco Chronicle). Protein powders often contain additives and unwanted ingredients, lacking enough nutrition to serve as your sole fuel source. Additionally, excessive protein shake consumption might lead to weight gain due to higher calorie content, according to Livestrong.
Liquid calories are easy to overconsume since they don’t feel as heavy. This reminds us of the golden rule in fitness and nutrition: moderation. In moderation, protein shakes may aid weight loss. Without control, they could lead to weight gain (via Mayo Clinic). How you manage this is your choice.
You could be consuming heavy metals
This is where it gets concerning. According to Medical News Today, 2013 research linked protein overconsumption to kidney and bone issues and even increased cancer risk. A Consumer Reports analysis found some protein powders contain toxic heavy metals. Contaminants like mercury, arsenic, cadmium, and lead were found. Consuming these metals daily in large amounts could have serious consequences, as explained by Medical News Today.
Wondering how companies sell protein powders with such harmful ingredients? It’s simple: protein powders are considered nutritional supplements, not regulated like food. They’re subject to fewer and lenient tests compared to medications and food in the U.S. because the FDA “is not authorized to review dietary supplement products for safety and effectiveness before they are marketed.” To avoid negative health effects, it’s best to consume protein shakes as part of a colorful, healthy diet, according to Medical News Today.
You might have gas
If you’ve ever guzzled a whey protein shake and experienced stomach bloating, rest assured, it’s common. “While protein itself doesn’t increase flatulence, protein supplements may contain other substances that make you gassy,” explains Healthline. Those familiar with fitness or the #gymlife know this well.
Whey and casein-based powders, in particular, may contain significant lactose. Even those who tolerate dairy might experience digestive discomfort after a large lactose dose (via Healthline). Additives, including artificial sweeteners, can exacerbate the issue.
Relying solely on protein shakes might strain your social life. There’s only so much time one can spend in the company of lactose-induced odors.
You could have diarrhea
Diarrhea is an unpleasant but common side effect of consuming too much protein or something that disrupts your system. Like flatulence, an occasional bout of diarrhea may follow protein intake with excess lactose or sugar alcohols (via Healthline).
As noted by Medical News Today, diarrhea can also indicate excessive protein consumption. Athletes or those with demanding jobs might need more than the recommended protein amount, but some people’s bodies struggle with high protein intake. Generally, protein itself won’t cause diarrhea unless consumed excessively over time. However, excess protein consumption is linked to diseases beyond gastrointestinal issues, such as heart disease. Therefore, relying solely on protein shakes is ill-advised.
Your metabolism will experience some problems
Obtaining all nutrients from a single food source is challenging. Relying solely on protein shakes could result in an imbalanced diet (via Medical News Today). This might seem counterintuitive, especially if you’re consuming protein shakes for health reasons. However, something beneficial in moderation might not remain healthy when consumed excessively.
Without essential nutrition, your metabolism might become unbalanced, as explained by Medical News Today. This could reverse progress made. While sweeteners in protein shakes are fine in moderation, overconsumption may cause insulin spikes.
The golden rule of nutrition remains: moderation. Excessive protein intake can lead to kidney issues, blood sugar imbalances, and nutrient deficiencies (via Medical News Today). Aim for a varied diet, not just chocolate peanut butter shakes.
You might burden your kidneys
Overconsumption typically taxes bodily systems. People often joke about harming their liver with excessive alcohol, but alcohol isn’t the only beverage causing organ damage.
If you only drank protein shakes, your kidneys would be overworked. They process and break down protein (per BioTech USA). Overconsumption forces them into overdrive, potentially leading to long-term effects.
Healthy kidneys can endure overconsumption for a while before facing consequences. However, those with kidney disease shouldn’t follow a high-protein diet. The kidneys may struggle to eliminate waste necessary for protein processing (via Mayo Clinic), potentially causing a health decline.
Too many protein shakes could lead to acidosis
Our bodies prefer a pH level of 7.35 to 7.45. Slight fluctuations can cause harm, illnesses, and death (via News-Medical).
Your kidneys regulate many pH-balanced systems. Overconsumption of protein might hinder their ability to maintain these systems. Though rare, acidosis can result from excessive protein intake, as a study in the Journal of the International Society of Sports Nutrition found. Symptoms include fatigue, weakness, irritability, and more (Healthline).
To consume abundant protein without risking acidosis, experts at BioTech USA recommend a balanced diet. They suggest pairing protein with ample vegetables to prevent this condition.
Overconsumption can lead to many illnesses
While diarrhea and gas seem minor, excessive protein intake poses bigger risks. Medical News Today reports that many doctors link protein overconsumption to type 2 diabetes, cancer, and osteoporosis. Severe risks include cardiovascular disorders, liver disease, seizures, and even death.
Protein is essential but produces waste that must be properly managed. Overwhelming our systems with protein reduces their functionality, increasing disease risk. While avoiding all diseases forever is impossible, consuming protein mindfully can promote longevity and health. With great protein comes great responsibility. Experts at Medical News Today advise consuming protein in moderation to prevent permanent health damage.
