Is Smoothie King Good for protein?

Protein is an important macronutrient that plays many vital roles in the body. It helps build and repair tissues, produces enzymes and hormones, and builds muscle mass. Many people aim to increase their protein intake through diet, especially those looking to gain muscle from strength training. Smoothies have become a popular way to add more protein to one’s diet. Smoothie King is one of the largest smoothie franchises in the world, with over 1,000 locations across the United States. But are Smoothie King smoothies actually a good source of protein?

Smoothie King’s Protein Options

Smoothie King offers several smoothie options with added protein. Their menu includes:

  • Gladiator – Whey protein smoothie
  • Slim-N-Trim – Whey protein smoothie for weight loss
  • Strawberry X-Treme – Whey protein smoothie
  • Chocolate X-Treme – Whey protein smoothie
  • Vanilla X-Treme – Whey protein and soy protein smoothie
  • Muscle Punch – Whey protein and soy protein smoothie

The Gladiator, Slim-N-Trim, and X-Treme smoothies can be customized to include 20g, 30g, 40g, or 50g of whey protein. The Muscle Punch smoothie contains 25g of proteins from whey and soy.

Smoothie King uses whey protein isolate and soy protein isolate as their protein sources. Whey and soy proteins are complete proteins, meaning they contain all nine essential amino acids.

Benefits of Whey and Soy Proteins

Here are some benefits of the proteins used in Smoothie King smoothies:

Whey Protein

  • Contains high levels of branched-chain amino acids (BCAAs) – leucine, isoleucine, valine
  • Absorbs quickly and easily in the body
  • Can aid muscle protein synthesis and recovery from exercise
  • High in the amino acid cysteine which boosts glutathione levels – a potent antioxidant
  • Helps increase feelings of fullness and reduces appetite

Soy Protein

  • Complete protein provides all essential amino acids
  • Plant-based option suitable for vegetarians/vegans
  • May help lower LDL (bad) cholesterol levels
  • Contains isoflavones that act as phytoestrogens which may reduce risk for some hormone-related cancers

Consuming a combination of both whey and soy proteins can provide complementary benefits.

Protein Content of Smoothie King Smoothies

The protein content of Smoothie King smoothies ranges from 20-50 grams per 20-24 ounce smoothie.

Here are the protein stats for a few of their smoothie options in 20 ounce servings:

Smoothie Protein (grams)
Gladiator – 20g protein 20g
Gladiator – 50g protein 50g
Slim-N-Trim – 20g protein 20g
Slim-N-Trim – 50g protein 50g
Strawberry X-Treme – 20g protein 20g
Strawberry X-Treme – 50g protein 50g
Chocolate X-Treme – 20g protein 20g
Chocolate X-Treme – 50g protein 50g
Vanilla X-Treme – 20g protein 20g
Vanilla X-Treme – 50g protein 50g
Muscle Punch 25g

As you can see, the protein content can vary widely depending on the specific smoothie and size ordered. In general, Smoothie King smoothies contain 20-50g of high-quality whey and soy protein per 20 ounce serving when protein is added.

Daily Protein Needs

How does this stack up to your daily protein requirements? Protein needs vary based on many factors including gender, age, activity level, goals, and health status.

The recommended daily allowance (RDA) for protein is:

  • Men age 19-70: 56g/day
  • Women age 19-70: 46g/day

However, these RDAs are minimums. Many experts recommend higher intakes for active individuals and athletes:

  • Sedentary people: 0.5-0.6g protein per pound bodyweight
  • Active people: 0.6-0.8g per pound
  • Athletes: 0.8-1g per pound or more

So a Smoothie King smoothie with 20-50g protein provides a significant amount of your daily protein needs, depending on your individual goals.

For a 150 pound person, here is how Smoothie King protein smoothies may meet daily needs:

Smoothie Protein Protein % Daily Needs (Sedentary) Protein % Daily Needs (Active)
20g protein 22-27% 14-18%
25g protein 28-33% 17-22%
30g protein 33-40% 20-25%
40g protein 44-53% 27-33%
50g protein 55-67% 33-42%

As you can see based on the table, a Smoothie King smoothie with 20-50g of protein can provide anywhere from 22% up to 67% of a 150 pound person’s protein needs for the day. Higher protein smoothies from Smoothie King may fit better into an active person or athlete’s daily protein goals.

Protein Quality

Getting enough total protein is important, but protein quality also matters. As mentioned earlier, Smoothie King only uses high-quality isolated whey and soy proteins, not cheaper protein concentrates or blends.

Isolated proteins have higher protein content, over 90%, compared to 70-85% for concentrates. This means less lactose and fat. Isolates also digest and absorb quicker.

Both whey and soy proteins have high scores on common protein quality scales:

  • Protein Digestibility Corrected Amino Acid Score (PDCAAS): Whey and soy both score a perfect 1.0, like meat, eggs, and milk. This means their proteins contain adeqaute amounts of all essential amino acids.
  • Biological Value (BV): Whey rates a 104 and soy rates a 74. Higher than meats like beef at 80.
  • Net Protein Utilization (NPU): Whey rates a 92 and soy rates a 61. Comparable to eggs at 88.

Based on these quality ratings, the proteins in Smoothie King smoothies are highly bioavailable to support muscle building and recovery.

Cost Analysis

One downside is the high cost of Smoothie King smoothies with extra protein. Prices vary by location, but on average a 20 ounce smoothie with protein costs $8-10.

At this price point, here is the cost per gram of protein:

Smoothie Protein Average Cost Cost Per Gram Protein
20g $8 $0.40
25g $8.50 $0.34
30g $9 $0.30
40g $9.50 $0.24
50g $10 $0.20

At $0.20-$0.40 per gram of protein, Smoothie King is one of the more expensive ways to get your protein compared to food sources like chicken breast ($0.05 per gram), whey protein powders ($0.07 per gram), eggs ($0.12 per gram), and Greek yogurt ($0.15 per gram).

However, some may find the convenience and taste of a Smoothie King smoothie worth the extra cost. Adding fruits and other ingredients also increases the price but provides nutritional benefits beyond just protein.

Nutrients & Ingredients

In addition to quality protein, what else is in Smoothie King smoothies?

Their smoothies include a mix of fruits, juices, nuts, seeds, supplements, sweeteners, and ice. Some examples of ingredients:

  • Fruits: strawberries, bananas, pineapple, mango
  • Vegetables: spinach
  • Juices: apple juice, orange juice, cranberry juice
  • Nuts & seeds: almonds, peanut butter
  • Sweeteners: honey, agave nectar, pure cane sugar
  • Supplements: whey protein, soy protein, glutamine, creatine
  • Ice
  • Water

Smoothie King claims their smoothies contain one full serving of fruit per 20 ounces. Their smoothies provide a more balanced nutrient profile compared to straight whey protein shakes.

However, some ingredients like juices and added sugars increase the calorie and carbohydrate counts, so adjustments can be made if watching weight. Dietitian tip: request light juice and fresh fruit instead of added sugars.

Benefits of Smoothies

There are additional benefits that make smoothies like Smoothie King a good choice:

  • Blend of fruits, vegetables, and protein is more nutritious than a protein shake alone
  • Liquid form allows for fast digestion and absorption
  • Cold temperature is refreshing and palatable
  • Convenient and portable
  • Various flavor options to prevent taste fatigue
  • Can customize with fat-burning or muscle-building ingredients like spinach, nut butters, flaxseed

Smoothies like those from Smoothie King provide a more enjoyable way to get in high-quality proteins and nutrients compared to protein powders or supplements alone. This may promote more consistent intake and help people meet their fitness goals.

Potential Downsides

Some potential downsides to consider with smoothies:

  • Cost is higher compared to making protein shakes and meals at home
  • Pre-made smoothies lack fullness of whole foods and may cause blood sugar spikes
  • Easy to over-consume calories, juices, and sugars if portion sizes not controlled
  • Not ideal as a full meal replacement for active individuals
  • Some ingredients like fruit juices may be counterproductive for weight loss goals
  • Social and environmental aspect of meals is lost

To prevent these downsides, consume Smoothie King smoothies in moderation as part of an overall healthy diet, not as your sole source of nutrition. Adjust smoothie ingredients to align with your nutrition goals.

Should You Drink Smoothie King Smoothies?

Here is a summary of the pros and cons:


  • High protein content from 20-50g of high-quality whey or soy protein
  • Greater protein than the RDA – good for active lifestyles
  • Blend of fruits and nutrients more balanced than just protein powder
  • Convenient, portable meal or snack
  • Promotes consistency for people who dislike protein shakes
  • Variety of flavors prevents taste fatigue
  • Can customize with fat-burning or muscle-building ingredients


  • Expensive at $0.20-$0.40 per gram protein
  • High calorie, sugar, carbohydrates if not conscious of portions and customizations
  • Not as filling as whole food meals
  • Some ingredients like fruit juice may hinder weight loss goals
  • Easy to consume excess calories
  • Loss of social aspect of eating


Overall, Smoothie King smoothies can be a convenient option to increase daily protein intake from high-quality whey and soy protein sources. But they may not be the most cost-effective solution for all individuals.

For active individuals struggling to meet protein needs through whole foods alone, Smoothie King smoothies provide a more enjoyable, portable way to add 20-50g of protein on-the-go. But even active populations should not solely rely on smoothies and require well-balanced whole food meals with adequate protein.

Those looking to lose weight need to be more conscious of ingredients like fruit juices, added sugars, and overall calorie counts in smoothies. Lower protein options or customizing with fresh fruits and vegetables may better align with weight loss goals.

In the end, Smoothie King smoothies in moderation can complement an already protein-rich diet for some populations like athletes and bodybuilders. But they should not serve as your only source of nutrition. Focus on getting protein from whole foods first and smoothies second. Monitor your total calorie intake, ingredients, and portion sizes to obtain the benefits of Smoothie King smoothies for protein without adverse effects.

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