ketohackers / metabolic flexibility
An evidence-first field guide to low-carb and ketogenic eating for builders and founders: how ketones fuel the brain, how to dose MCT oil and electrolytes sensibly, and how to read your own glucose data.
Check with your doctor before changing your diet if you have diabetes or take glucose-lowering medicines (insulin, sulfonylureas or SGLT2 inhibitors, which can cause dangerous ketoacidosis on a very low-carb diet), take medicines for blood pressure, have kidney, liver, pancreas or heart disease, are pregnant or breastfeeding, or have a history of eating disorders. This site is educational and does not replace medical care.
01 / mechanism
In the classic 1967 fasting study, ketones replaced glucose as the brain's main fuel after several weeks without food. On a ketogenic diet the brain still uses some glucose, which the liver keeps making.
02 / converter
Supplement labels mix compound weight and elemental weight, which makes dosing confusing. Enter what you take and see the elemental sodium, potassium and magnesium, compared with general reference values.
Reference values are for the general adult population, not keto-specific targets. Ask your doctor what is right for you, especially if you have high blood pressure, heart or kidney disease, or take blood pressure medicines or diuretics.
Caprylic acid (C8) produces about three times the ketone response of capric acid (C10). Studies suggest starting at about 5 g and building towards 15 to 20 g if tolerated; stomach upset and diarrhoea are the main side effects (Lin et al., 2021).
WHO advises adults to keep sodium below 2,000 mg a day and to get at least 3,510 mg of potassium, mainly from food. The US upper limit for magnesium from supplements is 350 mg a day.
Potassium supplements can be dangerous with kidney disease or with some blood pressure medicines (ACE inhibitors, ARBs, potassium-sparing diuretics). Get potassium from food unless your doctor advises otherwise.
03 / self-measurement
A continuous glucose monitor reads glucose in the fluid under the skin every few minutes. Readings lag behind blood glucose by several minutes, so look at curves, not single numbers.
CGM availability and prices differ by country; ask a pharmacist or your doctor.
Published monographs · 研究专著与公开方案
Autophagy, β-Hydroxybutyrate and the Bioenergetics of Intermittent Fasting
Cahill's fuel switch, autophagy and its limits in humans, ketones in the brain, Veech's thermodynamics checked by calculation, NAD+ and sirtuins, a model of common fasting schedules and a pre-registered crossover trial on attention. It names no brand, recommends no supplement and gives no doses.
从卡希尔燃料切换、自噬及其在人体的证据边界，到维奇热力学的核算与 NAD+，附糖原–酮体模型与预注册交叉试验；书中不提任何品牌、不推荐补充剂、不给剂量。
Not medical advice. Disclosure: this site and 5D Library are run by the same group, founded by the author. 非医疗建议。说明：本站与 5D Library 同属作者创办的集团。
Alpha-Quartz, Tourmaline Pyroelectricity, Widmanstätten Diffusion and Near-Infrared Cytochrome c Oxidase
The real physics behind stones and light, and how large it is: the piezoelectricity of quartz and the quartz resonator, the pyroelectricity of tourmaline, the Widmanstätten pattern as a record of cooling over millions of years, light in tissue and the biphasic dose of red and near-infrared light, the Schumann resonances and earthing, with four physical checks and a double-blind trial against a heat-matched sham.
石英压电与谐振器、电气石热释电、魏德曼花纹记录的百万年冷却、组织光学与红光近红外的双相剂量、舒曼共振与接地，附四项物理检测与等热量假照射双盲试验。
Not medical advice; the book claims no healing power for any stone, meteorite, earthing product or light device. Disclosure: this site and 5D Library are run by the same group, founded by the author. 非医疗建议；本书不声称任何石头、陨石、接地产品或光照设备有疗效。说明：本站与 5D Library 同属作者创办的集团。
Dopamine Reward Prediction Error, Serotonergic Homeostasis, HPA-Axis Allostatic Load and the Challenge Hypothesis, Read Beside East Asian Classics of Mind Regulation
Dopamine as reward prediction error and the average-reward model of a raised baseline, the HPA axis and allostatic load as a feedback loop, testosterone and the challenge hypothesis with honest effect sizes, serotonin, morning light and the circadian clock, slow breathing near 0.1 Hz and the baroreflex, and why no single hormone level is optimal, read beside Mencius, the Suwen and Zhuangzi's wooden cockerel, with a daily-rhythm check and a pre-registered trial of morning light and slow breathing.
多巴胺作为奖励预测误差与平均奖励率模型、HPA 轴负反馈与异态负荷、睾酮与挑战假说的真实效应量、血清素与晨光授时、0.1 Hz 慢呼吸与压力反射共振，以及为什么不存在单一的最优激素水平，与《孟子》养气、《素问》恬惔虚无和《庄子》木鸡并读，附日常节律核查与晨光加慢呼吸的预注册随机试验。
Not medical advice; the book gives no hormone, drug or supplement doses. Disclosure: this site and 5D Library are run by the same group, founded by the author, who uses these books as the basis of his community courses, the 5D Ascension Cards (Dimensional Shift Card Decks) and the Yafu AI knowledge base. 非医疗建议；本书不给任何激素、药物或补充剂剂量。说明：本站与 5D Library 同属作者创办的集团，作者以这些书作为其社群认知课程、升维牌卡（5D Ascension Cards）与 Yafu AI 知识库的方法论基础。
From the Randle Cycle and Epigenetic Inhibition to Autophagy Kinetics, Read Beside Classical Chinese Fasting Texts
Ketone bodies as fuel, signal and switch: fuel stoichiometry and why ketones yield less ATP per molecule of oxygen than glucose, Veech's thermodynamic hypothesis computed with the Nernst equation, β-hydroxybutyrate and histone deacetylases and how later work revised that finding, the AMPK–mTORC1 switch and why mouse autophagy timelines are not human hours, calorie-matched metabolic-ward trials, and sodium and water in the first low-carbohydrate week, read beside the Mawangdui Quegu shiqi, Ge Hong's Baopuzi and the Huangdi Neijing, with a four-step metabolic log and a pre-registered crossover trial.
酮体作为燃料、信号与开关：燃料化学计量与「按每分子氧计酮体的 ATP 产量低于葡萄糖」、用能斯特方程计算维奇的热力学假说、β-羟丁酸与组蛋白去乙酰化酶及其后来的修正、AMPK–mTORC1 开关与「小鼠自噬时间线不等于人的小时数」、热量匹配的代谢舱试验，以及低碳水第一周的钠与水分变化，与马王堆《却谷食气》、葛洪《抱朴子》和《黄帝内经》并读，附四步代谢记录与预注册随机交叉试验。
Not medical advice; the book gives no supplement or ketone-ester doses and its exercises never go beyond a 16-hour daily fast. Disclosure: this site and 5D Library are run by the same group, founded by the author, so he has a direct commercial interest in the book's subject; the book mentions and recommends no product. 非医疗建议；本书不给任何补充剂或酮酯剂量，练习不超过每天 16 小时的进食间隔。说明：本站与 5D Library 同属作者创办的集团，作者与本书主题有直接的商业利益关系；书中不提及也不推荐任何产品。
From the Gompertz Mortality Law and Mitohormesis to Cardiorespiratory Fitness Epidemiology, Read Beside Classical Chinese Longevity Philosophy
Takes apart the popular story that autophagy, hormesis and 'Zone 2' push back the mortality curve: the Gompertz–Makeham law and reliability theory, the mTORC1–AMPK–ULK1 switch and when damage really accumulates, what hormesis does and does not mean, the inconsistent replication of 'antioxidants block the benefits of exercise', the epidemiology of cardiorespiratory fitness (with its headline hazard ratios read correctly), reverse causation and the null Generation 100 trial, read beside the Lüshi Chunqiu, the biography of Hua Tuo and the Suwen, with a four-step recovery checklist and a pre-registered randomised trial.
把「自噬、毒物兴奋与 Zone 2 能推迟死亡率曲线」的流行故事逐段拆开：冈珀茨—梅克姆定律与可靠性理论，mTORC1—AMPK—ULK1 开关与损伤何时真正堆积，毒物兴奋效应的定义与边界，「抗氧化剂阻断运动益处」没有一致重复，心肺适能流行病学（正确解读其风险比）、反向因果与 Generation 100 试验的阴性结果，与《吕氏春秋·尽数》「流水不腐，户枢不蝼」、《三国志·华佗传》《素问》并读，附四步恢复核查表与预注册随机对照试验。
Not medical advice: it recommends no drug, supplement or extreme fasting and gives no doses; get a cardiovascular check-up before starting vigorous exercise. Disclosure: this site and 5D Library are run by the same group, founded by the author, who uses these books as a methodological reference for his community courses, the 5D Ascension Cards (Dimensional Shift Card Decks) and the Yafu AI knowledge base. The same group runs ketohackers.com and nadplusnadplus.com, so the author has a direct commercial interest in this subject; the book names no brand or product. 不是医疗建议：不推荐任何药物、补充剂或极端禁食，不给任何剂量；开始高强度运动前请先做心血管检查。说明：本站与 5D Library 同属作者创办的集团，作者以这些书作为其社群课程、升维牌卡（5D Ascension Cards）与 Yafu AI 知识库的方法论参考。同一集团运营 ketohackers.com 与 nadplusnadplus.com，作者与本书主题有直接商业利益；书中不提及任何品牌或产品。
No. People with diabetes, especially those on insulin, sulfonylureas or SGLT2 inhibitors, people with kidney, liver or pancreatic disease, pregnant or breastfeeding women and anyone with a history of eating disorders should talk to their doctor before starting.
Nutritional ketosis is a moderate rise in blood ketones, commonly described as about 0.5 to 3 mmol/L. Ketoacidosis is a medical emergency with much higher ketones and acidic blood, usually linked to a lack of insulin. They are not the same thing.
No. They raise blood ketones for a few hours, but a well-formulated low-carbohydrate diet produces ketones on its own. MCT oil is optional and often causes stomach upset at high doses.
It can show how your glucose responds to specific meals, sleep and exercise. Readings in people without diabetes are not a diagnosis; take any unusual pattern to a doctor.
One email a week: a paper summarised in plain words, a measurement method, and what we changed in our own logs. No supplements to sell.
Educational content only. Nothing on this site is medical advice or a claim that any diet, food or supplement prevents, treats or cures any disease. Speak to a registered doctor or dietitian before making major changes to your diet, especially if you have a medical condition or take medicines.