Topic
Nutrition & Protein
Research on protein requirements, timing and diet composition — including myths like 'high protein harms kidneys'.
Research
Related research
- Randomized controlled trialConfidence: Low2014
High-Protein Overfeeding and Body Composition in Trained Individuals: An 8-Week RCT
Antonio J, Peacock CA, Ellerbroek A, Fromhoff B, Silver T / Journal of the International Society of Sports Nutrition
Key point: No significant within- or between-group changes in body mass, fat mass, lean mass, or body fat percentage
- Randomized controlled trialConfidence: Moderate2014
Alcohol Ingestion Impairs Maximal Post-Exercise Rates of Myofibrillar Protein Synthesis following a Single Bout of Concurrent Training
Parr EB, Camera DM, Areta JL, Burke LM, Phillips SM, Hawley JA, Coffey VG / PLOS ONE
Key point: トレーニング後のアルコール摂取（1.5g/kg体重相当）は筋線維タンパク質合成を最大24%抑制した
- Randomized controlled trialConfidence: Moderate2015
Food Order Has a Significant Impact on Postprandial Glucose and Insulin Levels
Shukla AP, Iliescu RG, Thomas CE, Aronne LJ / Diabetes Care
Key point: 野菜・タンパク質・脂質先食い群は炭水化物先食い群と比較して食後30分・60分の血糖値が有意に低かった
- ReviewConfidence: Moderate2015
Effects of intermittent fasting on body composition and clinical health markers in humans
Tinsley GM, La Bounty PM / Nutrition Reviews
Key point: 16〜24時間の断食では、タンパク質摂取量が確保されていれば顕著な筋タンパク質分解は起きにくい
- Randomized controlled trialConfidence: Moderate2009
Ingestion of whey hydrolysate, casein, or soy protein isolate: effects on mixed muscle protein synthesis at rest and following resistance exercise in young men
Tang JE, Moore DR, Kujbida GW, Tarnopolsky MA, Phillips SM / Journal of Applied Physiology
Key point: ホエイはカゼイン・ソイと比較してレジスタンス運動後の筋タンパク質合成を有意に高めた
- ReviewConfidence: Moderate2016
B vitamins and energy metabolism: roles, deficiencies, and supplementation effects — a review
Kennedy DO / Nutrients
Key point: B vitamins are essential cofactors in ATP production, the TCA cycle, and fatty acid β-oxidation
- Meta-analysisConfidence: High2015
Folic acid supplementation for prevention of neural tube defects: a meta-analysis of randomized trials
De-Regil LM, Peña-Rosas JP, Fernández-Gaxiola AC, Rayco-Solon P / Cochrane Database of Systematic Reviews
Key point: Folic acid supplementation reduced NTD risk by approximately 72% (relative risk 0.28)
- Meta-analysisConfidence: High2014
Iron Deficiency and Aerobic Exercise Performance: A Systematic Review and Meta-analysis
Pasricha SR, et al. / British Journal of Haematology
Key point: Iron supplementation improved VO2max by an average of +3.9 ml/kg/min (95% CI: 1.9–5.9)
- Meta-analysisConfidence: Moderate2016
Effects of L-Carnitine Supplementation on Fat Metabolism, Exercise Performance, and Body Composition: A Meta-Analysis
Pooyandjoo M, et al. / Obesity Reviews
Key point: Significant but small reduction in body weight vs placebo
- Randomized controlled trialConfidence: Moderate1996
Effects of Zinc Supplementation on Testosterone Levels and Immune Function
Prasad AS, et al. / Nutrition
Key point: In zinc-deficient older men, testosterone approximately doubled with supplementation (recovery within normal range)
- ReviewConfidence: Moderate2017
Branched-chain amino acids and muscle protein synthesis in humans: myth or reality?
Wolfe RR / Journal of the International Society of Sports Nutrition
Key point: BCAA alone can theoretically stimulate MPS by up to ~30%, but missing EAAs limit actual anabolic impact
- Meta-analysisConfidence: High2018
Protein supplementation augments resistance-training-induced gains in muscle mass and strength (meta-analysis)
Morton RW, et al. / British Journal of Sports Medicine
Key point: Protein adds to lean-mass and strength gains
Supplements
Related supplements
Chia Seeds
Confidence: ModerateChia seeds (Salvia hispanica)
A superfood rich in plant-based omega-3 (ALA), dietary fiber, calcium, and protein. However, ALA converts to EPA/DHA at low efficiency — not a substitute for fish-derived omega-3.
Digestive Enzymes
Confidence: ModerateMulti-enzyme blend: protease, amylase, lipase, lactase, etc.
Enzyme products supporting food digestion and nutrient absorption. Beneficial when enzyme production is reduced (exocrine pancreatic insufficiency, aging, certain GI conditions). Benefits for healthy individuals are more limited.
Egg White Protein
Confidence: ModerateEgg white (albumin) protein
Dehydrated egg white in powder form. Dairy-free, making it an alternative for those who cannot use whey or casein. Digestion speed is intermediate between whey and casein.
Flaxseed (Linseed)
Confidence: ModerateFlaxseed (Linum usitatissimum seeds)
Seeds rich in ALA omega-3, lignans (phytoestrogens), and dietary fiber. Ground flaxseed has better nutrient absorption than whole seeds.
Grass-Fed Whey Protein
Confidence: ModerateWhey protein derived from grass-fed cows
Whey derived from cows raised exclusively on grass. Slightly higher in omega-3 fatty acids and conjugated linoleic acid (CLA) compared to conventional whey.
Green Powder (Greens Blend)
Confidence: LowMulti-ingredient blend: wheatgrass, barley grass, spirulina, chlorella, vegetables, fruits, etc.
Blended powder of multiple vegetables, grasses, and algae. Used as a convenient option to supplement vegetable intake, but composition varies widely by product and cannot fully replace fresh vegetables.
Green & Red Powder Blend
Confidence: LowMulti-ingredient blend: greens (vegetables, grasses) + reds (berries, fruits)
A blended powder combining greens (vegetables, grasses) and reds (berries, fruits). Designed to cover a broader range of antioxidants including anthocyanins and polyphenols beyond typical greens-only products.
Inulin
Confidence: ModerateInulin (chicory root-derived fructan)
A soluble dietary fiber (prebiotic) from chicory root. Serves as food for intestinal bifidobacteria and lactobacilli, improving gut microbiota. Blunts post-meal blood glucose spikes and supports satiety.
Iron
Confidence: HighIron (ferrous fumarate, iron bisglycinate, etc.)
Essential mineral for hemoglobin synthesis in red blood cells. Iron deficiency is common in endurance athletes (especially women and distance runners); supplementation in deficient individuals significantly improves endurance and fatigue.
Moringa
Confidence: LowMoringa (Moringa oleifera) leaf powder
A plant called the "miracle tree" for its high concentration of vitamins, minerals, essential amino acids, and antioxidants (isothiocyanates). Studied for anti-inflammatory, blood sugar regulation, and antioxidant effects — large-scale human trials are still limited.
Niacin (Vitamin B3)
Confidence: ModerateNicotinic acid (niacin)
The acid form of vitamin B3. Functions as an energy metabolism cofactor; at high doses (1–3 g/day), studied for lipid-improving effects including HDL elevation, LDL reduction, and triglyceride lowering.
Niacinamide (Nicotinamide)
Confidence: ModerateNiacinamide (nicotinamide — amide form of vitamin B3)
The amide form of vitamin B3, without the flushing side effect of niacin. A precursor to NAD+/NADH involved in energy metabolism, DNA repair, and cellular signaling. At high doses, shows distinct properties from niacin.
Paprika Powder
Confidence: LowDried Capsicum annuum (paprika) powder
Dried and powdered red/yellow peppers (Capsicum annuum). Rich in vitamin C, carotenoids (beta-carotene, capsanthin), and antioxidants. Used as a culinary spice to increase nutritional density of meals.
Psyllium Husk
Confidence: HighPsyllium husk (Plantago ovata seed husk)
A psyllium seed husk with high viscous soluble fiber. Forms a gel in the gut with extensive research backing for cholesterol absorption reduction, blood sugar regulation, and bowel regularity.
Pumpkin Seed
Confidence: LowPumpkin seeds (Cucurbita pepo seeds)
Seeds rich in zinc, magnesium, iron, omega-6 fatty acids, and plant protein. Researched for prostate health, overactive bladder, and urinary symptoms; traditionally used for men's health support.
Vitamin B12
Confidence: HighCobalamin (methylcobalamin, cyanocobalamin, etc.)
A water-soluble vitamin essential for nerve function, red blood cell production, and DNA synthesis. Found only in animal products — vegans and vegetarians are at high deficiency risk and supplementation is strongly recommended.
Whey Protein Isolate
Confidence: HighWhey protein isolate (WPI)
A highly purified whey fraction with 90%+ protein, minimal lactose and fat. Suitable for those with lactose intolerance who want fast-digesting protein.
Zinc Picolinate
Confidence: ModerateZinc picolinate
A chelated zinc form bound to picolinic acid. Some research indicates higher absorption than zinc oxide or sulfate. Zinc's role in testosterone levels, immune function, and protein synthesis is well-studied.
Zinc
Confidence: HighZinc (zinc gluconate, zinc oxide, zinc sulfate, etc.)
An essential mineral required for 300+ enzymatic reactions. Involved in immune function, protein synthesis, reproductive health, and wound healing. Deficiency leads to reduced strength, testosterone, and immune function.
Casein Protein
Confidence: HighCasein (Micellar Casein / Calcium Caseinate)
Casein protein is a milk-derived protein characterized by slow digestion and absorption over 6 to 8 hours. Research suggests that pre-sleep casein intake may enhance muscle protein synthesis overnight. Combining casein with whey protein is thought to optimize both immediate and prolonged amino acid delivery.
MCT Oil (Medium-Chain Triglycerides)
Confidence: LowMedium-chain triglycerides (C8 caprylic acid, C10 capric acid)
A refined oil derived from coconut or palm kernel oil, concentrated in medium-chain fatty acids (C8 and C10). It is absorbed more rapidly than long-chain fats and may be converted in the liver into ketone bodies for use as a fast-acting energy source. Research suggests potential benefits for fat oxidation and appetite suppression when paired with a low-carbohydrate diet, though effect sizes are small and long-term evidence remains limited.
Soy Protein
Confidence: ModerateSoy protein (isolate / concentrate)
A plant-based complete protein containing all nine essential amino acids, studied as a practical option for those with dairy allergies or following a vegan diet. Leucine content is somewhat lower than whey, which may result in a slightly smaller muscle protein synthesis response, but research suggests it is a useful tool for meeting total daily protein targets.
Folate
Confidence: HighFolate (vitamin B9, including methylfolate)
A water-soluble B vitamin (B9) essential for DNA synthesis and methylation. A Cochrane meta-analysis reports that folate supplementation before and during early pregnancy lowered the relative risk of neural tube defects (spina bifida, anencephaly) by about 72%. Because the neural tube closes around weeks 3–4, supplementing before pregnancy is considered important.
Vitamin B Complex
Confidence: ModerateB vitamins (B1, B2, B3, B5, B6, B7, B9, B12)
A collective term for eight B vitamins. Reviews describe each as an essential coenzyme in mitochondrial ATP production, the TCA cycle, fatty-acid β-oxidation, and amino-acid metabolism. Deficiency causes neurological symptoms, dermatitis, or anemia, but added benefit for already-replete healthy people is limited. Being water-soluble, excess is excreted and toxicity risk at usual doses is low.
Vitamin B-50
Confidence: ModerateB vitamins balanced at around 50 mg/µg each
A higher-dose formula that balances the B vitamins at roughly 50 mg/µg each. The underlying roles (coenzymes in energy metabolism) are based on the same review. Supplementation is meaningful for deficient people, while added benefit for the replete is limited. Because each component is dosed high, upper-limit awareness matters more.
Whey Protein
Confidence: HighWhey protein
A convenient way to top up protein that's hard to hit through meals alone. Rich in leucine, which helps trigger muscle protein synthesis. A supplement to total intake — not a magic powder.
Articles
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