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Nutrition and Metabolic Factors
Published in Michael H. Stone, Timothy J. Suchomel, W. Guy Hornsby, John P. Wagle, Aaron J. Cunanan, Strength and Conditioning in Sports, 2023
Michael H. Stone, Timothy J. Suchomel, W. Guy Hornsby, John P. Wagle, Aaron J. Cunanan
A typical American diet consists of approximately 9–16% of the total caloric intake being made up of protein (96, 163). However, many athletes, particularly strength-power athletes, may increase these values to approximately 15–25% of their total caloric intake (112, 214, 215). Proteins are relatively complex molecules that have a variety of enzymatic and structural functions related to body growth, maintenance and repair, and energy production. Under normal resting conditions, only about 1–2% of the total energy required is supplied by protein; however, it should be noted that greater quantities of protein may be used as an energy source if dietary carbohydrate and fat become inadequate fuel sources (105). In this light, skeletal muscle serves as a reservoir for protein and can be catabolized for energy in situations such as starvation (198) or long-distance endurance events, such as a marathon (199).
Molecular adaptation to resistance exercise
Published in Adam P. Sharples, James P. Morton, Henning Wackerhage, Molecular Exercise Physiology, 2022
Even though myofibrillar protein synthesis increases following a single bout of resistance exercise, if training is performed in the fasted state, the increase in muscle protein degradation will be greater than the increase in protein synthesis, resulting in a negative protein balance (Figure 8.3). Protein balance only becomes positive, and thus muscle fibre hypertrophy only occurs, in the presence of sufficient essential amino acids, such as following a meal (17). Amino acid intake and the molecular regulation of protein synthesis after exercise are covered in detail in Chapter 10. Briefly, consuming essential amino acids not only increases muscle protein synthesis, but also decreases protein breakdown following resistance exercise, suggesting that the increase in protein breakdown following resistance exercise in the fasted state occurs in order to supply essential amino acids for protein synthesis. Since essential amino acids only come from the diet or stored protein, they must be supplied by breaking down existing protein if insufficient protein has been ingested. Therefore, following resistance exercise in a fasted state, more protein must be degraded to produce the precise amino acid mix necessary to synthesize novel proteins. With training, muscles become better at recycling amino acids resulting in better overall protein balance in the fasted state (18).
Macronutrients
Published in Chuong Pham-Huy, Bruno Pham Huy, Food and Lifestyle in Health and Disease, 2022
Chuong Pham-Huy, Bruno Pham Huy
Briefly, adequate protein intake is necessary to support the increased production of antibodies for fighting infection. Insufficient protein intake decreases the resistance of body to microbes, parasites, and chronic diseases. In contrast, eating more protein than we need does not improve immune function (3).
The development of peptide- and oligonucleotide-based drugs to prevent the formation of abnormal tau in tauopathies
Published in Expert Opinion on Drug Discovery, 2023
Madia Lozupone, Vittorio Dibello, Rodolfo Sardone, Fabio Castellana, Roberta Zupo, Luisa Lampignano, Ilaria Bortone, Roberta Stallone, Mario Altamura, Antonello Bellomo, Antonio Daniele, Vincenzo Solfrizzi, Francesco Panza
Between small molecules and proteins, peptides are a particular class of pharmaceutical compounds. Proteins are huge biomolecular constituted by one or more long chains of amino acid residues. Proteins are important regulators of biological functions including the transport of chemicals, giving a structure to cells and organisms, the response to stimuli, replication of DNA, and a catalysis of metabolic reactions. Peptides, with high biological activity, selectivity, and low toxicity, can be created by the enzymatic protein digestion, have often fewer than 20–30 amino acid residues, and represent a viable alternative to chemical compounds. In vivo, unfortunately, peptide medicines have short half-life and proteases generally rapidly destroyed these compounds. This factor can substantially impedes their clinical development, constituting challenges for administration and transport, in particular to the brain [77].
Effect of Whey Protein Supplementation on Perioperative Outcomes in Patients with Cancer—A Systematic Review and Meta-Analysis (PROSPERO 2020: CRD42020188666)
Published in Nutrition and Cancer, 2022
Nivedhyaa Srinivasaraghavan, Nairita Das, Kalpana Balakrishnan, Swaminathan Rajaram
Six MWKT has been found to be a valid tool for assessing the functional recovery of patients after colorectal surgeries (48). The results show that there was a significant functional improvement in the intervention group as compared to the control group before surgery (after a period of prehabilitation) and this was sustained at four weeks after surgery. Whey protein could have assisted in enhancing the lean body mass of patients thus improving functional outcomes in the perioperative period. This is substantiated by the fact that inadequate protein intake impairs normal metabolic function and results in muscle wasting (49). Consequently, muscle wasting can decrease the six-minute walk distance (50). 6MWKT cannot however be a substitute for cardiopulmonary exercise testing which is an objective indicator of a patient’s functional capacity and a monitor of the various organs involved in the exercise. 6MWKT is ideal for patients who have a moderate to severe functional impairment and the perioperative period in cancer fits this scenario (50). While two trials included in the review used 6MWKT at eight weeks as an outcome (39, 40), it was not analyzed as an outcome in this meta-analysis because of the missing data as patients failed to return to the hospital at eight weeks for follow-up after surgery (40).
Effects of cinnamaldehyde on glucose-6-phosphate dehydrogenase activity, some biochemical and hematological parameters in diabetic rats
Published in Biomarkers, 2022
Remzi Çelik, Handan Mert, Bahat Comba, Nihat Mert
Proteins have an important role in cell structure and function. The amount of protein in the blood depends on the balance between the rate of synthesis and the rate of catabolism or loss (Hamad et al.2009). Albumin is the most abundant protein in plasma (Marshall et al.2004) and has been reported to fall in the inflammatory process, chronic inflammatory diseases, genetic defects, liver diseases, malnutrition, malabsorptive diseases (Whitby et al. 1984). Inflammatory status has been reported during diabetes mellitus (Vishakha and Shilpa 2011). This may be one of the reasons leading to the decline of albumin observed in diabetes (Hathama and Aymen 2015). In addition, one of the causes of reduction is hemodilution. This occurs in diabetic patients (Wang et al.2008), who suffer from an increase in urine due to high blood glucose, because of the pumping of water from the cell to the bloodstream, which causes an increase in the formation of urine and dilution of the glucose and protein concentration. They reported that total levels of protein and albumin decreased significantly and that globulin levels increased significantly in patients with Type 1 and Type 2 diabetes (Hathama and Aymen 2015).