James Rutherford

AI chatbots provide dangerous levels of medical misinformation🚨 This new study investigated responses of 5 popular AI chatbots… 👉 Gemini 👉 DeepSeek 👉 Meta AI 👉 ChatGPT 👉 Grok Chatbots were prompted with 10 questions from five categories (cancer, vaccines, stem cells, nutrition and athletic performance) and were assessed for scientific accuracy 🔍 Results 📊 👉 49.6% of responses were problematic 👉 30% were somewhat problematic 👉 19.6% were highly problematic Response quality did not differ significantly among chatbots. …BUT Grok generated significantly more highly problematic responses than would be expected under a random distribution ⚠️ 💉 Performance was strongest in vaccines and cancer questions ❌ Performance was worst in stem cells, athletic performance and nutrition AI is highly prone to providing medical misinformation, especially in the athletic performance and nutrition domain‼️ If you want reliable, trustworthy and evidence-based information, ask a qualified and experienced practitioner ✅ Reference: pubmed.ncbi.nlm.nih.gov/4198… Subscribe to Performance Nutrition Digest FREE to receive your daily study breakdown, straight to your inbox or via the Substack app 📥 performancenutritiondigest.c… Performance Nutrition Digest is powered by Healthspan Elite⚡️ healthspanelite.co.uk/

Nutritional considerations across the menstrual cycle and for hormonal contraceptive use 📝 This new review highlighted the key scientific literature on nutrition for female athletes… …distinguishing important differences between eumenorrheic menstrual cycles and hormonal contraceptive users Here are the key takeaway points ⬇️ ENERGY INTAKE 🔥 🩸 Eumenorrheic Intake may increase in the luteal phase (+100–300 kcal/day) Target: >45 kcal/kg FFM/day 💊 Hormonal Contraceptive Use Energy intake may appear more stable but remains individualised Target: >45 kcal/kg FFM/day CARBOHYDRATE 🍞 🩸 Eumenorrheic Possible luteal-phase alterations in glycaemic regulation Post-exercise: ~1.2 g/kg; During exercise: 30–60 g/hour to compensate for reduced gluconeogenesis in luteal phase 💊 Hormonal Contraceptive Use Glucose handling may vary by formulation Prioritise low-GI carbohydrates where appropriate during active pill weeks to mitigate transient insulin resistance PROTEIN 🥩 🩸 Eumenorrheic No meaningful phase-dependent differences in MPS Target: 1.4–2.2 g/kg/day; Post-exercise: ~0.32–0.38 g/kg 💊 Hormonal Contraceptive Use No clear differences between active and pill-free phases Target: 1.4–2.2 g/kg/day; Post-exercise: ~0.32–0.38 g/kg INFLAMMATION / SYMPTOMS 💥 🩸 Eumenorrheic Luteal phase may increase fatigue, cravings, and discomfort Vitamin D, zinc, and curcumin may support symptom management 💊 Hormonal Contraceptive Use May reduce symptom severity in some individuals; responses vary HYDRATION💧 🩸 Eumenorrheic Progesterone-related fluid retention and bloating may occur 💊 Hormonal Contraceptive Use Fluid shifts and bloating may vary by individual and formulation GI TOLERANCE 💨 🩸 Eumenorrheic GI symptoms may fluctuate across the menstrual cycle 💊 Hormonal Contraceptive Use GI tolerance may improve or worsen depending on individual response IRON STATUS 💉 🩸Eumenorrheic Menstrual blood loss increases iron deficiency risk Estimated requirement in endurance athletes: ~30 mg/day 💊 Hormonal Contraceptive Use Reduced bleeding may lower deficiency risk Supplement based on biomarkers; some formulations provide iron OVERALL PRACTICAL IMPLICATIONS ✅ 🩸 Eumenorrheic Align nutrition with training load, energy availability, and symptom presentation rather than phase-based assumptions 💊 Hormonal Contraceptive Use Does not guarantee metabolic stabilisation; individualised monitoring remains essential Reference: pubmed.ncbi.nlm.nih.gov/4197… Subscribe to Performance Nutrition Digest FREE to receive your daily study breakdown, straight to your inbox or via the Substack app 📥 performancenutritiondigest.c… Performance Nutrition Digest is powered by Healthspan Elite⚡️ healthspanelite.co.uk/

The evidence for carnivore diets in sport 🥩🔍 This new review summarised the available evidence for carnivore and animal-based diets for sport 📚 So, does the evidence match up to the marketing claims? 🤔 Here is the science ⬇️ Reduced systemic inflammation 🛡️ 🧠 Theory: Removing plant compounds (e.g. “antinutrients”) lowers inflammation 📚 Evidence: Partial (from ketogenic diets only) 👉 Reality: No direct evidence in athletes ❌ Evidence strength: Low Stable energy availability ⚡ 🧠 Theory: Less blood glucose fluctuation + greater fat reliance 📚 Evidence: Seen in low-carb models 👉 Reality: No direct carnivore data ⚠️ Evidence strength: Low–moderate (indirect only) Improved body composition ⚖️ 🧠 Theory: High protein + ketosis → fat loss, lean mass retention 📚 Evidence: Supported in general low-carb / high-protein research 👉 Reality: Not unique to carnivore diets ✅ Evidence strength: Moderate (but indirect…) Enhanced recovery 🔁 🧠 Theory: Reduced gut irritation + removal of “problem foods” 📚 Evidence: Conflicting findings 👉 Reality: No clear performance or recovery benefit ❌ Evidence strength: Very low Improved endurance efficiency 🏃 🧠 Theory: Higher fat oxidation → better fuel sustainability 📚 Evidence: Consistent metabolic adaptation 👉 Reality: Does NOT reliably improve performance ❌ Evidence strength: Low High-intensity performance 🚫 🧠 Theory: Reduced carb availability can support performance adequately 📚 Evidence: Consistently negative in low-carb literature 👉 Reality: Reduced glycogen = impaired high-intensity output ❌ Evidence strength: Low (primarily against) There is limited to no direct evidence that carnivore diets are suitable for athletes or those engaging in sport ⚠️ The hype does not stand up to scientific scrutiny ❌ Reference: pubmed.ncbi.nlm.nih.gov/4190… Subscribe to Performance Nutrition Digest FREE to receive your daily study breakdown, straight to your inbox or via the Substack app 📥 performancenutritiondigest.c… Performance Nutrition Digest is powered by Healthspan Elite⚡️ healthspanelite.co.uk/

Pre-season energy expenditure of professional football players ⚽️🔥 This new study investigated energy expenditure of pro football players across a 14-day preseason period using doubly labelled water 🔍 Which encompassed a… 🥅 Training only week 🏆 Training + match week Here is what they found ⬇️ Average energy expenditure values across the full 14-day period were… 🔥 Total energy expenditure = 3167 ± 313 kcal/day 🫀 Resting energy expenditure = 1902 ± 213 kcal/day ⚽️ Active energy expenditure = 1004 ± 246 kcal/day 📊 Physical activity level was therefore 1.67 For dietary intake across this period, players consumed on average… 🍽️ Total energy intake = 2617 ± 363 kcal/day 🍞 Carbohydrate = 2.8 ± 0.6 g/day 🍖 Protein = 2.2 ± 0.4 g/day 🥑 Fat = 1.5 ± 0.4 g/day Total energy expenditure and dietary intake was not significantly different between training-only and training+match weeks ❌ Professional football players likely do not achieve energy balance or consume enough carbohydrates 🪫 The more data I see alongside personal experience working with pro athletes, the more I think that the vast majority are chronically underfuelling and over consuming protein 🚨 So much athletic potential and health is left out on the table due to this issue ‼️