Explore how a daily cup of lightly roasted coffee could tip the scales in favor of better body composition for those struggling with weight, with slight yet promising reductions in fat and boosts in muscle mass.

Study: Consumption of Coffee Rich in Phenolic Compounds May Improve the Body Composition of People with Overweight or Obesity: Preliminary Insights from a Randomized, Controlled, and Blind Crossover Study. Image Credit: Narong Khueankaew / Shutterstock.com

In a recent study published in Nutrients, researchers in Spain evaluated the effects of consuming polyphenol-rich coffee on the body structure of overweight or obese individuals.

New strategies in the fight against obesity

Obesity is a significant public health concern, as it can increase the risk of non-communicable diseases like type 2 diabetes, ischemic heart disease, and cancer. Furthermore, obesity has a crucial role in metabolic syndrome, which encompasses insulin resistance, dyslipidemia, and high blood pressure.

Genetics, chronobiology, and microbiome contribute to the development of obesity. As a result, effective treatment requires a multifaceted approach that includes lifestyle adjustments and increased physical exercise.

New techniques, such as polyphenol-rich meals, may help reduce fat mass while improving long-term adherence and reducing adverse treatment effects. Hydroxycinnamic acids, monocaffeoylquinic, dicaffeoylquinic, and chlorogenic acids are important polyphenols with numerous health benefits, some of which include cholesterol reduction, better glucose metabolism, and antioxidant and anti-inflammatory properties.

About the study

Individuals between 18 and 65 years of age with body mass index (BMI) values between 25 and 35 kg/m² were invited to participate in the current randomized control trial (RCT) from October 2022 to May 2023. Smokers, individuals following vegetarian or vegan diets, pregnant or lactating women, those who consumed antibiotics in the previous two months, and those who recently changed their physical activity or dietary habits were excluded from the study.

Roasted coffee (RC) arabica beans from Colombia were used for commercial use, and experimental lightly roasted coffee (LRC), which was roasted for shorter durations to increase its polyphenol content while retaining organoleptic qualities, was used. The study involved consuming three cups of RC or LRC daily for 12 weeks, including a two-week washout period before each intervention. RC preparation involved adding seven grams to a coffee machine, whereas LRC involved 14 grams added to 200 mL of boiling water.

High-performance liquid chromatography using online diode detectors (HPLC-DAD) was used to analyze coffee samples. LRC contained 130 mg of caffeine and 400 mg of hydroxycinnamic acids for each cup, whereas RC comprised 70 mg of caffeine and 50 mg of hydroxycinnamic acids for each cup. Study participants consumed 1,200 mg/day of polyphenols from LRC and 450 mg/day from RC.

The trial involved six visits, during which researchers examined clinical history, medication usage, blood pressure, anthropometric measurements, serum biochemistry, and body composition. Serum samples were also used to measure high-density lipoprotein (HDL), triglycerides (TG), and fasting blood glucose (FBG) levels.

Anthropometric measures included height, weight, BMI, and waist circumference. Body composition parameters included fat mass in kilograms and percent, skeletal muscle mass in kilograms and percent, and visceral fat area.

All study participants’ diets were monitored through phone interviews and 24-hour recall, whereas physical activity levels were monitored with accelerometers. Linear mixed models calculated the mean differences in intervention effects.

Study findings

After ingesting the two coffees, the body fat percentage decreased by 1% and 1.4% in the RC and LRC groups, respectively, whereas skeletal muscle mass grew modestly by 0.7% and 0.8%, respectively. LRC consumption led to a 33.9% fat reduction compared to the RC group’s 34.7%.

Although LRC led to a modest increase in fat mass as compared to commercial RC, the difference was non-significant. Visceral fat in the RC group was not significantly altered, whereas that of LRC consumers remained near the threshold for significance. Skeletal muscle mass and percentage slightly increased in both groups; however, neither coffee variety led to an increase in skeletal muscle mass or percentage.

Body weight and metabolic syndrome characteristics did not differ significantly. Reductions in systolic and diastolic blood pressure levels were also not statistically significant in either group.

The health benefits of lightly roasted coffee

Gently roasted coffee is more efficient in altering body composition, especially in overweight or obese individuals. In the current study, both experimental and control coffees significantly reduced body fat percentage and improved muscle mass, thus suggesting that lightly roasted coffee induces beneficial changes in adipose tissue. Furthermore, moderate intake of polyphenol-rich coffee may reduce the detrimental effects of an imbalanced diet.

Future studies are needed to confirm these findings in larger sample sizes that also assess the differential impact of lightly roasted coffee on body composition, clinical biomarkers, genetic, metabolomic, intestinal microbiota, chronobiology, sleep quality, and dietary control.