Losing fat and building muscle | Alan Aragon, Msc

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Looking to lose weight and gain muscle with science-backed insights? Tune in to Episode #296 with nutrition researcher Alan Aragon to unpack the nuances of achieving optimal body composition. You’ll gain a deeper understanding of how to effectively use nutrition – balancing calories, protein, fats, carbohydrates, and even alcohol – to enhance your physique.

“The general population that’s left to their own devices is highly unsuccessful for weight loss, unfortunately.”

Alan Aragon is a highly esteemed nutrition researcher and educator with over three decades in the field. As a trailblazer in evidence-based nutrition for the fitness industry, Alan’s work has profoundly influenced nutrition and exercise practices. His extensive experience includes authoring the influential monthly research review (AARR) and co-authoring seminal works in sports nutrition. With his deep understanding of diets and body composition, Alan offers invaluable insights for anyone looking to optimize their fitness and health through scientifically grounded nutritional strategies.

“Most people would want to keep their weight lost to around 1-2 lb a week. Viewing one to two pounds a week as actually fast weight loss is a healthy thing to do.”

In this episode, discover the crucial role of resistance training, the importance of supplementation, and the myths around fasting and keto diets in muscle building and weight loss. Alan’s expertise will empower you with practical, science-backed strategies for sustainable body composition changes, whether you’re looking to lose weight, build muscle, or both.

“You can never really measure body composition. You ballpark estimate it. It’s an educated wild guess.”

Specifically, we discuss:

  • Introduction to Body Composition and Fitness Science (00:00)
  • How Alan Aragon’s Passion for Fitness Shapes His Evidence-Based Approach (3:34)
  • Debunking the Anabolic Window: Fact or Fiction? (7:32)
  • Impact of Meal Timing on Body Composition: A Scientific Analysis (12:28)
  • Comparing Fasted vs. Fed Resistance Training for Muscle Growth (22:51)
  • Understanding Amino Acids in Muscle Protein Synthesis (25:38)
  • Protein Needs Across Ages: A Comprehensive Guide (32:16)
  • Evaluating Amino Acid Supplementation at Varied Protein Intakes (39:16)
  • Calculating Optimal Protein for Different Age Groups and Body Weights (41:53)
  • Linking Protein Intake with Body Recomposition: A Scientific Perspective (47:33)
  • Methods to Determine Your Fat-Free Mass Accurately (58:12)
  • Muscle Building: Ketogenic Diet vs. High Carbohydrate Diet (1:02:04)
  • Energy Balance vs. Carbohydrate-Insulin: Diet Models Explored (1:08:03)
  • Keto Adaptation and Insulin’s Role in Weight Loss Explained (1:13:40)
  • Investigating the Rise in Overweight and Obesity Since the 1960s (1:23:33)
  • Optimal Fat Loss Strategies: A Science-Based Step-by-Step Guide (1:30:58)
  • Does Starvation Affect Metabolic Rate? Scientific Insights (1:39:30)
  • Integrating Fasting into Your Weight Loss Strategy (1:47:11)
  • Personalising Diet Plans: The Flexibility of Dieting (1:52:53)
  • Protein Intake and Longevity: Finding the Optimal Balance (1:55:26)
  • Soy Protein: Health Benefits and Controversies (1:58:00)
  • Protein Sources and Their Impact on Cardiometabolic Health (2:07:55)
  • Tailoring Weight Loss Programs for Maximum Satiety and Effectiveness (2:15:17)
  • Examining the Safety of Intermittent Fasting for Women’s Hormonal Health (2:22:53)
  • Effective Supplements for Enhancing Body Composition (2:30:44)
  • Alcohol’s Impact on Body Composition: Key Facts You Should Know (2:36:27)
  • Conclusion and Key Takeaways from Our Fitness Science Discussion (2:44:21)

A huge thank you to Alan Aragon for this conversation many years in the making. It’s been a unique opportunity to explore body composition, a topic we’ve not examined closely on The Proof before, and I hope this episode provided you with valuable insights and practical knowledge to support you on your journey towards optimal health.

Connect with Alan Aragon on Instagram and Twitter. Head to his website, https://alanaragon.com/, to learn more about his work, purchase his books, or subscribe to his newsletter.

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More about Alan Aragon

Alan Aragon is a nutrition researcher and educator with over 30 years of success in the field. He is a pioneer of evidence-based nutrition in the fitness industry, and is known as one of the most influential figures. His notable clients include Stone Cold Steve Austin, Derek Fisher, and Pete Sampras. Alan writes a monthly research review (AARR) providing cutting-edge theoretical and practical information. Alan has co-authored more than two dozen peer reviewed scientific publications, many of which shape the current practice guidelines of nutrition and exercise professionals. He co-authored Nutrient Timing Revisited, the most-viewed article in the history of the Journal of the International Society of Sports Nutrition (JISSN). He also is the lead author of the ISSN Position Stand on Diets & Body Composition.

Supporting studies:

Body fat percentage ranges

  • Healthy body weights: an alternative perspective • PMID: 8615340
  • Body composition interpretation. Contributions of the fat-free mass index and the body fat mass index • PMID: 12831945

Post-exercise anabolic window

  • Is There a Postworkout Anabolic Window of Opportunity for Nutrient Consumption? Clearing up Controversies • PMID: 30702982
  • Pre- versus post-exercise protein intake has similar effects on muscular adaptations • PMID: 28070459
  • Nutrient timing revisited: is there a post-exercise anabolic window? • PMID: 23360586

Protein distribution/intake per meal – maximising the acute anabolic response

  • How much protein can the body use in a single meal for muscle-building? Implications for daily protein distribution • PMID: 29497353

Age-related muscle-anabolic resistance

  • Age-related muscle anabolic resistance: inevitable or preventable? • PMID: 36018750

BCAA & EAA supplementations

  • Isolated Leucine and Branched-Chain Amino Acid Supplementation for Enhancing Muscular Strength and Hypertrophy: A Narrative Review • PMID: 33741748
  • Oral Branched-Chain Amino Acids Supplementation in Athletes: A Systematic Review • PMID: 36235655
  • International Society of Sports Nutrition Position Stand: Effects of essential amino acid supplementation on exercise and performance • PMID: 37800468

Protein intake requirements (total daily) for various populations

  • A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults • PMID: 28698222
  • International Society of Sports Nutrition Position Stand: protein and exercise • PMID: 28642676
  • A systematic review of dietary protein during caloric restriction in resistance trained lean athletes: a case for higher intakes • PMID: 24092765
  • Protein Recommendations for Weight Loss in Elite Athletes: A Focus on Body Composition and Performance • PMID: 29182451
  • Systematic review and meta-analysis of protein intake to support muscle mass and function in healthy adults • PMID: 35187864


Ketogenic diets and body composition effects

  • International society of sports nutrition position stand: diets and body composition • PMID: 28630601
  • Ketogenic diets, physical activity and body composition: a review • PMID: 34250885

Nutrient intakes of elite natural bodybuilders

  • Nutritional strategies of high level natural bodybuilders during competition preparation • PMID: 29371857

Carbohydrate-insulin model of obesity

  • Effect of Low-Fat vs Low-Carbohydrate Diet on 12-Month Weight Loss in Overweight Adults and the Association With Genotype Pattern of Insulin Secretion: the DIETFITS Randomized Clinical Trial • PMID: 29466592
  • Obesity Energetics: Body Weight Regulation and the Effects of Diet Composition • PMID: 28193517
  • Carbohydrates, insulin, and obesity • PMID: 33958466

Carb vs fat, controlled overfeeding (what happened to the carbs-are-fattening deal?)

  • Fat and carbohydrate overfeeding in humans: different effects on energy storage • PMID: 7598063
  • Macronutrient disposal during controlled overfeeding with glucose, fructose, sucrose, or fat in lean and obese women • PMID: 10919929

Burke et al’s well-controlled keto and performance research

  • Ketogenic low-CHO, high-fat diet: the future of elite endurance sport? • PMID: 32358802
  • Crisis of confidence averted: Impairment of exercise economy and performance in elite race walkers by ketogenic low carbohydrate, high fat (LCHF) diet is reproducible • PMID: 32497061

FASTER study showing similar glycogen levels between keto & control group in elite endurance athletes

  • Metabolic characteristics of keto-adapted ultra-endurance runners • PMID: 26892521

Slow weight loss (0.5-1.0% of total BW/week max) superior for preserving lean mass in lean/athletic subjects

  • Effect of two different weight-loss rates on body composition and strength and power-related performance in elite athletes • PMID: 21558571
  • Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation • PMID: 24864135
  • Achieving an optimal Fat Loss Phase in Resistance-Trained Athletes: A Narrative Review • PMID: 34579132

CALERIE Trial (showing 200-300 kcal decreases in NEAT at 6 months)

  • Effect of calorie restriction on the free-living physical activity levels of nonobese humans: results of three randomized trials • PMID: 21292847

Review of intermittent fasting (all variants) and body composition

  • Does Timing Matter? A Narrative Review of Intermittent Fasting Variants and Their Effects on Bodyweight and Body Composition • PMID: 36501050

Soy protein supplementation systematic reviews of relevance to the episode

  • Effect of Soy Protein Supplementation on Muscle Adaptations, Metabolic and Antioxidant Status, Hormonal Response, and Exercise Performance of Active Individuals and Athletes: A Systematic Review of Randomised Controlled Trials • PMID: 37603200
  • Neither soy nor isoflavone intake affects male reproductive hormones: An expanded and updated meta-analysis of clinical studies • PMID: 33383165

Recent vegan vs. omnivorous diet studies in resistance trainees consuming protein at  ~1.6 g/kg

  • Vegan and omnivorous High Protein Diets Support Comparable Daily Myofibrillar Protein Synthesis Rates and Skeletal Muscle Hypertrophy in Young Adults • PMID: 36822394
  • High-Protein Plant-Based Diet Versus a Protein-Matched Omnivorous Diet to Support Resistance Training Adaptations: A Comparison Between habitual Vegans and Omnivores • PMID: 33599941

Plant protein studies showing greater anabolic effects than animal protein

  • Mycoprotein ingestion stimulates protein synthesis rates to a greater extent than milk protein in rested and exercised skeletal muscle of healthy young men: a randomized controlled trial • PMID: 32438401
  • The Effects of Why vs. Pea Protein on Physical Adaptations Following 8-Weeks of High-Intensity Functional Training (HIFT): A Pilot Study • PMID: 30621129

Collateral fattening (excessive lean mass loss driving appetite dysregulation and eventual body fat regain)

  • Collateral fattening in body composition autoregulation: its determinants and significance for obesity predisposition • PMID: 29559726
  • Collateral fattening: When a deficit in lean body mass drives overeating • PMID: 28078821

Effectiveness of planned hedonic deviation (planned “cheating”)

Longer menstrual cycle in Intermittent energy restriction group:

  • The effects of intermittent of continuous energy restriction on weight loss and metabolic disease risk markers: a randomized trial in young overweight women • PMID: 20921964

Dietary impacts on testosterone levels

  • Low-fat diets and testosterone in men: Systematic review and meta-analysis of intervention studies • PMID: 33741447
  • Negative Consequences of Low Energy Availability in Natural Male Bodybuilding: A Review • PMID: 28530498
  • Manipulation of Dietary Intake on Changes in Circulating Testosterone Concentrations • PMID: 34684376

Whole eggs substantially increasing testosterone levels (vs egg whites)

  • Whole Egg vs. Egg White ingestion During 12 weeks of Resistance Training in Trained Young Males: A Randomized Controlled Trial • PMID: 33306586


  • International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine • PMID: 28615996

Fat burner supplements (low return on investment; high risk for reward)

  • Comparing effectiveness of fat burners and thermogenic supplements to diet an exercise for weight loss and cardiometabolic health: Systematic review and meta-analysis • PMID: 33427571
  • Dietary supplements for improving body composition and reducing body weight: where is the evidence? • PMID: 22465867

Influence of low sleep on appetite, energy intake, and obesity

  • Sleep deprivation in development of obesity, effects on appetite regulation, energy metabolism, and dietary choices • PMID: 37905402
  • The impact of sleep deprivation on food desire in the human brain • PMID: 23922121

Alcohol use disorder: abstinence vs moderation

  • Controlled drinking-non-abstinent versus abstinent treatment goals in alcohol use disorder: a systematic review, meta-analysis and meta-regression • PMID: 33188563

Red Wine

  • Health Effects of Red Wine Consumption: A Narrative Review of an Issue That Still Deserves Debate • PMID: 37111141

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