Mechanical tension, muscle damage, and metabolic stress are often viewed as the key stimuli for muscle hypertrophy. A new study asserts that mechanical activation of fast-twitch muscle fibers is the strongest determinant of muscle hypertrophy, which suggests that mechanical tension is the most noteworthy stimulus for muscle growth. This is an intuitive idea, but Greg’s segment explains why the results of this study fail to support the conclusions that were stated in the paper (and shared widely on social media). After that, Eric presents a segment that’s all about food selection. As flexible dieting and “IIFYM” continue to gain popularity, it’s indisputable that dieters can succeed using a virtually limitless variety of food sources, as long as they (approximately) hit their calorie or macro targets consistently. While it’s very true that dieters enjoy a great deal of flexibility in their food choices, this doesn’t mean that food source selection is irrelevant or inconsequential. In Eric’s segment, he discusses some evidence-based guidance for making food choices to facilitate a smoother dieting experience. SUPPORT THE PODCASTJoin the Research Spotlight newsletter: Get a two-minute breakdown of one recent study every Wednesday. Our newsletter is the easiest way to stay up to date with the latest exercise and nutrition science.MacroFactorIf you want to learn more about our MacroFactor diet app, check it out  here.To join in on the MacroFactor conversation, check out our Facebook group and subreddit.CoachingGet personalized training and nutrition plans from our expect coaches: Learn more hereMASS Research ReviewSubscribe to the MASS Research Review to get concise and applicable breakdowns of the latest strength, physique, and nutrition research – delivered monthly.Bulk SupplementsFinally, next time you stock up on supplements from BulkSupplements.com, be sure to use the promo code “SBSPOD” (all caps) to get 5% off your entire order. TIME STAMPSIntro/Announcements (0:00)Shampoo versus conditioner (2:15)Artificial intelligence for summarizing research (6:10)ConsensusElicitWhat’s the primary mechanism of muscle hypertrophy? (16:01)Confirmation bias (20:32)Abstract and summary of new study by Hatanaka and Ishii (22:46)Effect of resistance training mainly depends on mechanical activation of fast-twitch fiberEstimating the mechanical activation of fast twitch muscle fibers (27:47)How validation studies work (31:33)Exploring the equations used to estimate mechanical activation of fast twitch muscle fibers (34:30)Proposal and validation of mathematical model for resistance trainingImplications of the model used by Hatanaka and Ishii (41:18)Comparing and contrasting with longitudinal data (48:07)Muscle Failure Promotes Greater Muscle Hypertrophy in Low-Load but Not in High-Load Resistance TrainingConclusions (50:28)Flexible dieting and “IIFYM” work, but specific food selection still matters (58:25)Regulation of food intake (1:05:24)The satiety index (1:15:53)A satiety index of common foodsEffect Of Different Food Groups On Energy Intake Within And Between Individuals (1:18:43)Effect of different food groups on energy intake within and between individualsSome key food characteristics to consider (1:28:10)Ultra-Processed Diets Cause Excess Calorie Intake and Weight Gain: An Inpatient Randomized Controlled Trial of Ad Libitum Food IntakeTexture-based differences in eating rate influence energy intake for minimally processed and ultra-processed mealsTime to revisit the passive overconsumption hypothesis? Humans show sensitivity to calories in energy-rich mealsPractical applications (1:32:10)