Can Protein Shakes Sustain Your Entire Diet?

by Mara Welty July 19, 2023 7 min read

 person drinking invigor8 shake


Every day, our bodies require essential nutrients to help support our health and development. Typically, this consists of colorful meals complete with fresh vegetables, juicy fruits, hearty whole grains and protein-packed meats, nuts and seeds. And for those who find it difficult to reach the recommended 50 grams of daily protein, there are also protein shakes. 

Available in a variety of protein forms, from milk-based whey to plant-based soy, protein shakes are wonderful additions to any diet, especially if you’re looking to build muscle. Many protein shakes contain more than their protein source, too, with additional ingredients like greens, fatty acids and digestive enzymes.

As such, some nutrient-dense proteins can act as meal replacements, which may make some individuals wonder, can I live off of protein shakes? While they can certainly replace a meal or two, relying on protein shakes for all of your nutritional needs is not recommended. 

The Anatomy of Protein Shakes

Protein shakes are effective in delivering supplemental ingredients that contribute to weight loss support and muscle growth. They’re filled with amino acids — the essential building blocks of life, helping to:

  • Break down food
  • Build and repair body tissue and muscle
  • Stimulate hormones
  • Provide energy to the body 
  • Support skin, nail and hair health
  • Boost the immune system
  • Support the digestive system

Our bodies need 20 separate amino acids to carry out its daily functions, but only nine are essential, meaning our bodies will not produce them naturally. The only way we can get them is through the food (and protein shakes) we consume. These nine essentials include:

  • Histidine – This amino acid helps to create histamine, which plays a role in immunity, digestion, sleep and sexual health.
  • Isoleucine – Isoleucine plays a role in muscle metabolism, immune function, blood health and energy regulation.
  • Leucine – Leucine is responsible for producing protein and growth hormones and regulating blood sugar levels, as well as repairing muscles and wounds.
  • Lysine – This acid can assist in the production of hormones and energy.
  • Methionine – Methionine helps facilitate tissue growth, metabolism, detoxification and mineral absorption.
  • Phenylalanine – This amino acid helps create chemical messengers in the brain and other nonessential amino acids.
  • Threonine – Threonine is responsible for the health of the skin and connective tissues. It also helps the body form blood clots following injury.
  • Tryptophan – Tryptophan helps regulate and balance nitrogen levels in the body.
  • Valine – Valine helps support muscle growth and tissue regeneration.

While some protein shakes contain the basics, others go above and beyond in terms of ingredients. For example, the INVIGOR8 Superfood Shake contains:

  • Pure protein complex – Made from grass-fed whey protein, it’s high in nutrients and contains a complete amino acid profile. High-quality protein sources can support muscle growth and muscle recovery, reduce appetite, support bone health, increase fat burning and support healthy blood pressure.
  • Essential fatty acid complex – With flaxseed, chia and coconut oil, it’s rich in dietary fiber and fatty acids that support lean muscle growth. It may also help support metabolic, immune, bone, skin and oral health, as well as healthy blood sugar levels.
  • Superfood greens – Greens are a well-known boon to any diet. With kale, spinach, broccoli, alfalfa grass and algae, the shake is packed with essential vitamins and minerals to support overall health and provide nutritional goodness.
  • Immunity booster complex – Hormone-free colostrum, a nutrient-dense milk, helps support immune health, hormonal balance and digestive function.
  • Probiotics complex – A medley of lactobacillus, acidollphilus, bifidobacterium and bifidum help optimize digestion and support a healthy gut.
  • Digestive enzyme complex – People who are lactose intolerant may find it difficult to digest milk-based protein powders like whey and casein. Fortunately, the addition of digestive enzyme complex can help break down fats, proteins and carbohydrates so their nutrients can more easily absorb into the bloodstream.
  • Prebiotic fiber complex – Prebiotic fiber like chicory root extract can help you feel satiated, balance gut flora and prevent constipation.
  • Cognitive enhancers – L theanine and bacopa help facilitate oxygen and essential nutrient delivery to the brain and may also enhance cognitive performance.

The Limitations of Protein Shakes

Despite some protein shakes’ rich nutrient profile, protein shakes have their limitations. Relying on them solely can lead to:

  • Nutritional imbalances – Consuming only protein shakes can limit the number of essential nutrients your body relies on, as these nutrients are obtained from whole foods like fruits, vegetables, whole grains, nuts and seeds. Most protein shakes are low in carbohydrates, healthy fats, fiber, vitamins and minerals, and they cannot be considered a complete substitute for a balanced diet — even if you can use them to replace a couple of meals from time to time. If one were to only eat protein shakes for a long period of time, it might lead to nutrient deficiencies or imbalances. It may also limit the amount of antioxidants consumed, which the body needs to reduce oxidative damage and support full-body health.
  • Digestive issues – As previously mentioned, powders that contain lactose, such as whey and casein concentrate, may cause digestive discomfort, like bloating. Shakes that contain synthetic dyes, added sugar, preservatives, hormones, cheap protein, artificial flavors and artificial sweeteners might also have adverse effects on the gastrointestinal tract, and they may taste bad, too. 
  • Unsustainable eating practices – A diet that consists only of protein shakes is likely, not sustainable after a few weeks or months. Following a liquid-based diet over an extended period of time can feel and taste monotonous due to a lack of variety or dietary dissatisfaction. 

All that said, there is limited data regarding the effects of long-term protein powder use. However, most adverse effects are considered to be a result of contaminants in the protein powder. As such, it’s critical to review the ingredients of the protein product you’re using and ensure it’s tested by a third party before incorporating it into your diet.

The Benefits of Protein Shakes

While they shouldn’t comprise your entire diet, there is a time, place and need for protein shakes. As previously explored, we need to consume certain types of protein to deliver essential amino acids to the body. Their most critical role lies in building and repairing body tissue, namely muscles.

That’s why many athletes and workout enthusiasts incorporate protein shakes into their exercise routines. Following intense exercise and physical activity, muscle tissue can tear and break down. While this doesn’t sound too favorable, it’s actually critical to muscle growth. When muscles are damaged, the body uses its protein stores (amino acids) to support muscle recovery by repairing damaged muscle fibers, leading to growth and increased strength. 

That said, protein shakes aren’t only for the athletes. People who have a difficult time meeting their protein requirements, due to dietary restrictions such as vegetarianism or veganism, can consume daily protein shakes to supplement their whole-food protein intake. 

These types of shakes deliver a concentrated source of protein that the body can absorb relatively easily, depending on the type of protein. Whey protein is considered to be quickly absorbable — within 60 to 90 minutes — compared to other types of protein, such as:

  • Casein – Casein, which is another type of milk-based protein, is absorbed at a much slower rate, ranging from three to four hours. In terms of nutrition, a 33-gram scoop of casein protein powder contains 24 grams of protein and three grams of carbs. To compare, a 33-gram scoop of whey protein contains roughly 26.35 grams of protein and 2.64 grams of carbs. That said, nutrition extends beyond protein and carbs. To fully understand a protein’s nutritional value, you should also take fats, fiber, sugars, minerals and vitamins into account.
  • Egg – Egg proteins also absorb within three to four hours and are considered highly digestible. 33 grams of eggs contains 4.2 grams of protein and .24 grams of carbohydrates, although these numbers may differ when eggs are filtered into an isolate or concentrate. Isolate protein powders will not contain additional nutrients, only protein. As such, these types of protein powders are certainly not a feasible option when considering “Can you live off protein shakes?” That said, most protein sources, including soy, are available as concentrates, which still contain some amounts of carbs, fibers and fats.
  • Soy – Like egg and casein, soy protein can take three to four hours to enter your bloodstream and provide nutrients to the body. In its isolate form, it has 29.5 grams of protein per every 33-gram-scoop. Plant-based protein powders, which include soy in addition to pea, hemp, rice and seed protein, absorb more slowly than animal-based protein powders — with absorption rates that are typically 10 to 20 percent lower.

Protein powder is also considered an effective tool in body weight management. Since it’s satiating, it can help people feel full for longer periods of time and can mitigate cravings for unhealthy foods high in sugars or fats.

INVIGOR8 Shakes: Meal Replacements You Can Trust

Can you live on protein shakes? Certainly not, but you can incorporate nutrient-rich varieties into your diet to support your overall health. Most types of protein powders can even serve as a meal replacement if you’re on the go or looking for a high-protein start to your day.

The INVIGOR8 Superfood Shake is exactly what we’re talking about. With its bounty of natural protein powder ingredients, vitamins and minerals, it’s an effective superfood powder that can deliver muscle-boosting protein and body-supporting nutrients with every sip — alongside a balanced diet, of course.

For a boosted protein shake, choose INVIGOR8.


Healthline. Protein Intake — How Much Protein Should You Eat per Day?

Cleveland Clinic. Amino Acids

Healthline. 10 Science-Backed Reasons to Eat More Protein

Dioxyme. Protein absorption and bioavailability.

U.S. Department of Agriculture. 100% WHEY PROTEIN POWDER

The Washington Post. Ask a Doctor: Is animal protein easier to absorb than plant protein?

U.S. Department of Agriculture. Egg, whole, raw, fresh

U.S. Department of Agriculture. Soy protein isolate   

The INVIGOR8 Weight-Loss Family

Our weight-loss products all work great on their own, but they work even better together! Try our Superfood Shake in combination with our Collagen Peptides or Fat Burner to promote healthy weight loss.

See results in weeks, or your money back! Guaranteed!

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