Can Protein Coffee Help You Lose Weight?

Is proffee as effective for weight loss as influencers claim?

Let’s break it down by looking at what science says about coffee and protein individually.

Does Coffee Boost Metabolic Rate?

Research shows that caffeine increases metabolic rate, which can help you burn fat. For instance, a 2018 meta-analysis published in Critical Reviews in Food Science and Nutrition found that when people doubled their daily caffeine intake, they experienced a 22%, 17%, and 28% greater reduction in body weight, BMI, and body fat, respectively.

An impressive result at first glance—but bear in mind these reductions were relative, not absolute. That is, if you lost 1 pound in a week, doubling your coffee intake might have helped you lose 1.22 pounds.

An improvement, yes, but not a dramatic one.

The review also noted that while these effects were statistically significant, the actual weight loss was modest—around 4 pounds over 12 weeks at best. 

In short, drinking a lot more coffee can lead to a little more fat loss, provided you stick with it for several weeks, but the metabolic lift is far smaller and less impactful than high-protein coffee advocates claim.

Does Coffee Suppress Appetite?

Research shows that caffeine may slightly curb hunger, but its effect is probably too short-lived to matter. 

For example, a study published in the Journal of the Academy of Nutrition and Dietetics found that while people who consumed caffeine in the morning ate less at breakfast, they made up for it by eating more later in the day.

In other words, caffeine may blunt hunger for a short time, but the overall effect is too small and fleeting to make a meaningful dent in your overall calorie intake. So, like its effect on metabolic rate, caffeine’s influence on appetite won’t lead to substantial fat loss on its own.

Does Protein Boost Metabolic Rate?

Studies show that people who eat more protein while dieting lose more fat than those who eat less, even if the high-protein diet provides more calories overall.

For instance, a study conducted by the University of South Florida found that people who increased their daily protein intake from 0.7 to 1.1 grams per pound of body weight lost around 2.5 pounds of fat in 8 weeks. Surprisingly, they achieved this despite eating 250 more calories each day than usual.

Meanwhile, another group reduced their daily protein intake from 0.7 to 0.4 grams per pound of body weight over the same period. Despite reducing their daily calorie intake by 300 calories, they didn’t lose any fat.

Other studies show that switching to a high-protein diet can help you burn more calories (up to 80 more daily), and that increasing protein intake from ~0.4 to 0.8 grams per pound of body weight can boost fat loss by up to 2.4 pounds over 12 weeks, even if you don’t change anything else about your diet or exercise regimen. 

Researchers still don’t fully understand why protein has this effect, but the most accepted theory is that digesting protein increases metabolic rate because it “costs” more calories to process than carbs or fats.

Before you start heaping protein powder into your coffee expecting fat to melt away, here are two things to mull over.

First, while eating protein does increase fat loss, the effect is small. In the studies mentioned, people who ate more protein burned more fat, but the process was slow and wouldn’t have been big enough to noticeably change their appearance.

Second, the people in these studies made big changes to their overall protein intake. Just adding protein to your coffee won’t cut it—you’d need to make protein a much bigger part of your daily diet to see any benefit. 

Does Protein Suppress Appetite? 

A 2020 meta-analysis published in Physiology & Behavior reviewed 68 studies on protein and hunger. It found that while protein can reduce hunger and increase fullness at first, these effects fade over time—your body gets used to the higher protein intake, and the appetite-suppressing benefits dwindle.

The study also found that protein’s impact on appetite is most noticeable when people eat large amounts—around 35 grams or more per meal.

In other words, drinking high-protein coffee likely won’t make much difference unless you’re also consistently eating other large portions of protein throughout the day. Even then, the effect doesn’t last indefinitely, so relying on protein alone probably isn’t a long-term solution for controlling hunger.

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