MET-Rx
Peanut Butter Granola
TL:DR
In 2 Sentences
A true meal-replacement-scale bar: 28g of mixed dairy-and-soy protein, real oats and peanuts, a substantial carb load, and full vitamin–mineral fortification in a candy-bar-like wrapper.
When to choose MET-Rx Peanut Butter Granola
Choose it when you need a filling, portable meal—post-workout, on long workdays, or during travel—more than a tiny, low-sugar snack.
What's in the MET-Rx bar?
MET-Rx’s Big 100 Peanut Butter Granola bar eats like a small meal: a top-tier 28g of protein from a multi-source blend, paired with the highest carb load in our database and a calorie count to match.
The protein story is distinctly mixed—whey and milk protein isolates plus casein, supported by soy crisps, a touch of egg white, and even peanut flour—while the classic “peanut butter granola” vibe comes from peanuts, peanut flour, and rolled oats (with a chocolatey finish from cocoa and cocoa butter).
It’s also fully fortified with a vitamin–mineral blend. The headline: serious protein, serious carbs, and a layered ingredient list designed to keep the bar soft, sweet, and shelf-stable.
- Protein
- 28 g
- Fat
- 12 g
- Carbohydrates
- 48 g
- Sugar
- 14 g
- Calories
- 390
Protein
2815HIGHThe 28g of protein come from a Metamyosyn blend that combines whey and milk protein isolates with casein—then layers in soy protein crisps, a little egg white, and peanut flour. That mix gives you high-quality dairy amino acids (fast- and slow-digesting) with soy rounding out the profile, and the isolates keep lactose relatively low. The trade‑off is four major allergens in one bar (milk, soy, egg, peanut).
Fat
129HIGHFat here leans mixed: heart‑friendlier unsaturated fats from peanuts, sunflower and pumpkin seeds, flax, and canola/sunflower oils sit alongside more saturated fats from fractionated palm kernel oil, cocoa butter, and some milkfat. Expect an omega‑6 tilt from seed oils, with the coating‑style palm kernel/cocoa butter nudging saturated fat higher than nut‑butter‑only bars. Net: a blend of wholesome seed and nut fats plus some more processed, saturated sources.
Carbs
4820HIGHMost of the 48g of carbs come from refined binders and sweeteners (tapioca syrup and table sugar), a sugar alcohol for bulked sweetness, and glycerin for softness, then whole‑grain support from rolled oats and brown rice flour. You’ll feel a quick hit from the syrups, with some steadier energy from the oats, seeds, and added fiber. If your stomach is sensitive, know that sugar alcohols can cause bloating when portions get large.
Sugar
144HIGHYou get 14g of sugar, primarily from tapioca syrup and cane sugar, with a smaller contribution from naturally occurring milk sugars. The bar’s sweetness is also propped up by a sugar alcohol and glycerin—highly processed ingredients that add sweetness and moisture without raising the sugar number as much. That keeps label sugars moderate while total sweetness stays high; larger intakes of sugar alcohols can bother sensitive guts.
Calories
390210HIGHAt 390 calories, this reads as a small meal more than a light snack. Most of those calories come from the carbohydrate base (syrups and grains), with meaningful contributions from protein and fats in the nuts/seeds and oils. Great for long gaps between meals or post‑training refueling; if you’re nibbling, splitting the bar is an easy portion fix.
Vitamins & Minerals
This bar is heavily fortified: a vitamin–mineral premix lifts vitamins A, C, D, E and the B‑complex to about 25% DV, while minerals like zinc (≈35%), copper (≈60%), iron (≈20%), calcium (≈15%), iodine and phosphorus (≈25%) get a boost. Seeds and dairy add a bit of natural vitamin E and minerals, but most of the micronutrient heft comes from fortification.
Additives
Expect an engineered bar: humectants to keep it soft (glycerin), a sugar alcohol for bulked sweetness, added fiber (polydextrose), emulsifiers (soy lecithin), antioxidants to protect flavor (tocopherols), and a vitamin–mineral blend. These tools make a high‑protein bar that resists drying and crumbling, though they’re more processed than whole‑food binders. If you prefer simpler labels, this one sits at the more formulated end of the spectrum.
Ingredient List
Defatted soybean flakes
Cassava root
Cow's milk whey
Skim cow milk
Skim cow's milk
Eggs
Cassava starch
Sugarcane and sugar beet
Oat grain
Groundnut plant seeds
What are people saying?
Sources
Range
“I buy the Met-RX Big 100 bars because they’re 30-32 grams of protein and they’re quite tasty.”
“I actually buy their cookies n cream bars pretty often. Like the taste, high protein and live an active lifestyle (commute on bike + workout often) so the calories are pretty good for my needs.”
“My favorite of all time it the Met-Rx super cookie crunch bar. 100g Bar for 410 calories, 32g protein, 42g carbs, 14g fat. It’s high in sugar but once in a while it’s my sweet meal. They taste SO good and take me a long time to eat”
Main Praise
Fans keep coming back for three things: it actually satisfies hunger, delivers serious protein, and tastes better than a bar this big has any right to. Multiple reviewers say it’s substantial enough to serve as a meal stand-in, which lines up with the 28g of protein and nearly 400 calories.
On Amazon, Alex called it his go-to for size, texture, and macros, and even ranked flavors like Salted Caramel Brownie Crunch near the top. Ry singled out the Apple flavor for tasting authentically apple—refreshing and not overly sweet.
Redditors who bike to work or lift often say the calories work for them; one even noted it “takes a long time to eat,” which in bar-world is code for satisfying.
The broader verdict isn’t just anecdote either: with more than eleven thousand ratings averaging 4. 5 stars, Big 100 clearly delivers for people who need something heartier.
Main Criticism
The pushback clusters around sweetness, texture, and the level of processing. Some flavors run very sweet or a bit artificial; a few people notice a mild preservative note.
Texture can swing from pleasantly chewy to hard enough that several buyers warned to be careful with your front teeth, and there are isolated quality-control complaints about odd hard bits or underweight bars.
Sugar is a sticking point depending on flavor: this Peanut Butter Granola sits at 14g, but others in the line land higher, which won’t fit low-sugar goals. A handful of reviewers mention digestive discomfort, likely tied to sugar alcohols and glycerin used for sweetness and softness.
And allergen-wise, it’s a crowded label—milk, soy, egg, and peanut are all present.
The Middle Ground
Here’s where expectations matter. If you want a tiny, low-sugar nibble, Big 100 will feel like overkill; it was built to be food, not a dainty treat.
That helps explain the split reviews: CalypsoBrat and CriticalLootRNG rave about using it to power active days, while a Redditor with the charming handle im_a_dick_head calls out sugar and saturated fat.
Both takes have a point.
For long rides, double shifts, or post-lift recovery, fast-digesting carbs alongside 28g of protein and a mix of fats are practical; Men’s Health even highlights Big 100 as a legit high-calorie meal-replacement option, while Eat This, Not That!
likes the taste but flags higher sugar in some flavors. If you’re mostly desk-bound or sensitive to sugar alcohols, the sweetness and processing will feel like too much.
A simple compromise many people use: split the bar—half now, half later—and you still get the protein without committing to all 390 calories at once.
What's the bottom line?
MET-Rx Big 100 Peanut Butter Granola is exactly what it claims to be: a portable, sweet, chewy, vitamin-fortified, carb-forward meal with 28g of protein. It’s designed for hunger, not nibbling, and for people who want reliable fullness in a wrapper. Reviews consistently praise its staying power and the way it doubles as a post-workout refuel or a back-pocket lunch.
The trade-offs are equally clear. Sweetness is noticeable (though lower here than in some flavors), the ingredient list reads more engineered than rustic, and the texture can be firm. If you prioritize simple labels, minimal sweetness, or you’re avoiding milk, soy, egg, or peanut, look elsewhere.
But if you need a filling bar that actually performs like food, this one earns its spot—especially on days when your schedule doesn’t care that you’re hungry. Check the sugar by flavor, try the ones with better taste reviews, and don’t be afraid to make two snacks out of one bar.