New study reveals ground beef outperforms plant-based meat in muscle-building potential, challenging perceptions of protein power in plant alternatives.
Study: The anabolic response to a ground beef patty and soy-based meat alternative: a randomized controlled trial. Image Credit: DronG / Shutterstock.com
A recent study published in The American Journal of Clinical Nutrition compares the effectiveness of plant-based meat alternatives and ground beef in stimulating muscle protein synthesis (MPS).
Protein intake and anabolism
MPS, which is reflected by the fractional synthetic rate (FSR) of muscle protein, is a physiological process that is induced by protein consumption. MPS is crucial for renewing skeletal muscle by replacing older muscle cells with newer and more functional fibers, independent of increase in total muscle mass.
The largest rise in plasma essential amino acids (EAAs) occurs after consuming foods that have a greater content of bioavailable EAAs. Animal meat, for example, is an important source of protein that contains all EAAs needed for adult metabolism.
However, many people are switching to plant-based meat alternatives (PBMA), which are engineered to resemble the taste, texture, and appearance, and protein content of traditional meat products. Soy-based meat alternatives (SBMAs) are the most common type of PBMA, as these products have a relatively high protein content and favorable EAA profile. Nevertheless, SBMA does not induce the high and rapid increase in plasma EAAs after consuming meat.
Following the consumption of SBMA, plasma concentrations of EAA decline at a more rapid rate because EAAs are cleared by the splanchnic circulation. This may not affect the whole-body protein net balance; however, it reduces MPS.
About the study
The current study was a randomized controlled trial (RCT) that included individuals between 18 and 40 years of age with a body mass index (BMI) value between 20 and 32 kg/m2.
The FSR for muscle protein was used to measure MPS. Amino acids like phenylalanine (Phe), tyrosine (Tyr), and L-tyrosine (L-Tyr) were used as isotopic tracers to quantify their incorporation into new muscle protein.
Study participants were randomized to eat either one four-ounce ground beef patty (BP4), or one or two four-ounce soya-based meat alternative patties (SBMA-4 and SBMA-8, respectively). The whole-body rate of protein synthesis, whole-body protein breakdown rate, and net protein balance were calculated, in addition to measuring EAA levels in the blood.
Increased MPS with beef vs SBMA
Muscle protein FSR increased from the basal rate with BP4 and SBMA-8 consumption. MPS after BP4 consumption accounted for a larger proportion of whole-body protein synthesis as compared to SBMA-4 but not SBMA-8.
Protein breakdown rates were reduced in all three groups after protein intake, the lowest following SBMA-8 consumption. Smaller reductions were observed after beef and SBMA-4 consumption without inter-group differences.
Whole-body protein balance was higher in the SBMA-8 group as compared to the beef or SBMA-4 groups, both of which led to similarly small increases.
All EAA concentrations rose after protein consumption. However, the time to maximum concentration differed between the groups, with beef and SBMA-8 outperforming SBMA-4 in all respects, whereas beef was superior to SBMA-8.
Peak EAA blood concentrations were associated with changes in muscle FSR from basal levels following consumption of the patties. The FSR trend also correlated with whole-body protein synthesis.
How beef improves MPS
The mechanism underlying the stimulation of MPS by beef consumption as compared to PBMA remains unclear. Researchers have hypothesized that leucine triggers protein synthesis; however, both beef and SBMA-4 contained similar proportions of leucine, while the total leucine content was higher in SBMA-8. Moreover, the rise in plasma EAAs was similar for both beef and SBMA-8, thus limiting the plausibility of this theory.
Differences in the protein profile of beef and SBMA and their varying splanchnic clearance rates may account for the faster and higher rise in blood EAAs after beef consumption, which is proportional to the rise in MPS.
Carbohydrates enhance the MPS response in the presence of amino acids or protein. This suggests that the increased FSR with eight ounces of SBMA might be due to the increased intake of energy, rather than protein. However, while achieving similar FSR for MPS, SBMA-8 also supplied 60% more calories than BP4, which may limit the consumption of this product for weight-loss purposes.
Other macronutrient differences may have existed between the groups, as the response to whole foods was tested in the current experiment. Nevertheless, these results corroborate earlier observations indicating 47% higher MPS after eating a mixed or omnivorous meal as compared to a vegan meal.
Conclusions
The current study indicates that the effects of a four-ounce beef patty on the synthesis of muscle protein are emulated by eight ounces of SBMA patties that has a significantly lower caloric content by 60%. The rise in muscle protein FSR exceeded those observed following intake of a four-ounce SBMA patty.
Protein quality matters as much as quantity. This research underscores the fact that foods like nutrient-rich ground beef can offer more muscle-building benefits, and that’s critical as people make dietary choices, especially when balancing calorie intake.”
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