Consumption of High-Leucine-Containing Protein Bar Following Breakfast Impacts Aminoacidemia and Subjective Appetite in Older Persons

Abstract

Background Limited data are available examining dietaries for optimizing protein and leucine intake to stimulate muscle protein synthesis in older humans. Objectives We aimed to investigate the aminoacidemia and appetite responses of older adults after consuming breakfast, a meal frequently consumed with high-carbohydrate and below-par amounts of protein and leucine for stimulating muscle protein synthesis. Methods Five men and three women (means ± SD; 74 ± 7 y, BMI: 25.7 ± 4.9 kg∙m−2, fat- and bone-free mass: 63 ± 7 kg) took part in this experiment in which they consumed breakfasts with low-protein (LP = 13 ± 2 g), high-protein (HP = 32 ± 5 g), and LP followed by a protein and leucine enriched bar formulation two hours later (LP + Bar = 29 ± 2 g). The LP, HP, and LP + Bar breakfast conditions contained 519 ± 86 kcal, 535 ± 83 kcal, and 739 ± 86 kcal, respectively. Blood samples were drawn for six hours and analyzed for amino acid, insulin, and glucose concentrations. Visual-analog-scales were assessed for hunger, fullness, and desire to eat. Results The net AUC for EAA exposure was similar between the LP + Bar and HP conditions but greater in the HP condition versus the LP condition. Peak leucinemia was higher in the LP + Bar condition versus the HP, and both were greater than the LP condition. Net-leucine exposure was similar between HP and LP + Bar, and both were greater than LP. Hunger was similarly reduced in LP + Bar and HP, and LP + Bar resulted in a greater hunger reduction than LP. Both LP + Bar and HP resulted in greater net fullness scores than LP. Conclusions Consuming our bar formulation increases blood leucine avaiability and net exposure to EAA to a similar degree as consuming a high-protein meal. High-protein at breakfast results in a greater net exposure to EAA and leucine, which could support muscle protein synthesis in older persons.

Increased protein intake derived from leucine-enriched protein enhances the integrated myofibrillar protein synthetic response to short-term resistance training in untrained men and women: a 4-day randomized controlled trial

“…In concordance with the aminoacidemia and leucinemia in our previous work (Traylor et al 2021), the present study discovered that increasing protein intake through supplemental protein and leucine-enriched bar ingestion induced an additional increase in integrated rates of MyoPS during a unilateral lower-body resistance training protocol. We note that within a normal eating pattern a food matrix containing protein is consumed that blends whole food sources, and attenuates a rapid aminoacidemia/leucinemia response (Burd et al 2019).…”

“…The peak leucine concentration exceeded levels (~450 μM) reported to increase MyoPS in older adults (Murphy et al 2016) and after consuming 40 g of whey proteincontaining beverage (~320 μM) in younger adults (Yang et al 2012). The protein and leucine-enriched study bar elevated EAA and BCAA concentrations comparable to consuming a higher-protein meal (0.5 g protein/kg) (Moore et al 2015;Traylor et al 2021).…”

“…Leucine is an essential amino acid necessary for activating MyoPS via the mechanistic target of rapamycin (mTOR) signaling pathway in human skeletal muscle (Wolfson and Sabatini 2017;Wolfson et al 2016). Recently, we reported that consuming a protein and leucine-enriched bar -formulated with 16 g of a blend of micellar casein, whey protein, and whey protein hydrolysate -induced aminoacidemia comparable to consuming a single higher-protein-containing meal (0.5g of protein/kg) (Traylor et al 2021). Previous studies also reported that higher leucine-containing proteins enhance MyoPS and whole-body protein synthesis in young and older adults (Glynn et al 2010;Zaromskyte et al 2021).…”

“…After the leg press exercise and two minutes of rest, the participants performed the leg extension exercise in the same fashion. et al 2018a;Traylor et al 2021). Covance (Eurofins) produced the bars; their nutrient content is given in Table 2.…”

Wheat Biscuits Enriched with Plant-Based Protein Contribute to Weight Loss and Beneficial Metabolic Effects in Subjects with Overweight/Obesity

“…Administration of branched-chain amino acids (BCAAs) (i.e., L-leucine, L-isoleucine and L-valine) is also related to suppressed appetite [19]. Notably, enrichment of foods with L-leucine has shown great results regarding appetite perception in human beings, since their consumption leads to increased fullness and reduced hunger [20,21]. L-leucine suppresses food intake through regulation of neuropeptide Y/Agouti related peptide (NPY/AgRP) and proopiomelanocortin (POMC) release [22,23].…”