Functional nutrition bars are supplemental bars that provide essential nutrients and potentially offer clinical benefits to various bodily systems. They may promote bone, joint, skin, gut, nail, and immune health and may support athletic performance. Beyond their convenient delivery format and delicious taste, supplemental functional nutrition bars may also play a role in supporting overall metabolic health. 

Clinical studies have explored the potential benefits of nutrition bars to athletes. In a cross-over pilot study, 12 elite athletes were provided nutrition bars post-exercise for five consecutive days. They were given either a control bar or a protein bar with whey protein isolate, soy protein isolate, a high amount of dietary fiber, and some essential vitamins and minerals. When given the protein bar, the athletes displayed significantly reduced serum aspartate transaminase (AST) (a liver enzyme) and lactate dehydrogenase (LDH) and increased total and direct bilirubin status. These results suggest a decrease in exercise-induced muscle damage and an increase in antioxidant status, which is particularly relevant for physically active individuals.

A small open-label, randomized, counterbalanced, crossover trial with 12 resistance-trained men suggested that consuming a whey protein bar before, during, and after an exercise may promote healthy glucose metabolism, promote athletic performance, and potentially attenuate the perception of muscle soreness. However, these outcomes depend largely on the quality and constituents of the supplemental bar. 

Furthermore, a randomized, single-blinded cross-over study involving 23 women aimed to determine whether the consumption of a high-protein, high-fiber (HPHF) snack bar would influence food intake and glucose/insulin metabolism compared to a conventional isocaloric, high-fat, high-refined carbohydrate snack bar. These bars were consumed mid-morning and mid-afternoon alongside a standard breakfast and lunch. Nine hours after receiving the HPHF bar, the women’s glucose and insulin responses were significantly lower (P = 0.014 and P = 0.012, respectively), with peak glucose levels 16% lower than the conventional bar.  

Moreover, the same study indicated that the macronutrient composition of the bar impacted energy intake three hours after a subsequent meal. The HPHF bar was associated with a 5% reduction in energy intake at the next meal, potentially promoting a healthy appetite and post-meal satiety. However, it's important to note that this study did not include a "no snacking" group, so it remains unclear if adding bars affected total energy intake.

Finally, a clinical trial involving 25 healthy adults administered a nutrient-dense, low-calorie, high-fiber, fruit-based supplement bar twice daily for two weeks. Compared to the baseline, the adults experienced an increase in glutathione (20%) and high-density lipoprotein (HDL) cholesterol (6.2%), primarily due to a 28% increase in large HDL subparticles. They also demonstrated a decrease in homocysteine (19%), suggesting clinical benefits for metabolic health.

Functional nutrition bars may be an alternative delivery format for supplements to potentially help support overall metabolic health for the general population and athletes. Supplemental functional nutrition bars may promote overall health by containing higher levels of protein, fiber, antioxidants, and essential vitamins and minerals compared to conventional commercial bars.

By Danielle Moyer Male, MS, CNS, LDN