Tag: Knowledge recall

Much of eating runs on automatic processes: habits, cues, and cravings that arise before you have thought about them. Kahneman’s framework describes System 1 (fast, automatic, always running) versus System 2 (slow, deliberate, one thing at a time). Bargh’s automaticity research is widely cited for the claim that most behavior originates nonconsciously. On that account, deliberate resistance has to win every round against something that never stops. This companion covers the two systems, how this applies to eating, why conscious decisions fail, and working with the nonconscious rather than against it. (5 min read)

Metabolic adaptation is the body’s response to chronic calorie restriction: lowered metabolic rate, decreased energy expenditure, increased hunger. Research by Zauner found resting energy expenditure rising rather than falling in short-term fasting, from a small study; the larger one puts the rise at 6% by 36 hours, gone by 72, and absent in men. Fothergill’s study of Biggest Loser contestants showed metabolic suppression persisting 6 years after weight loss. In one study of a 36-hour fast, blocking growth hormone’s receptor suppressed fat mobilization while leaving protein metabolism unaffected. This companion covers the metabolic adaptation problem, the hormonal environments, why fasting…

The lipostat is the fat-regulation system a body is proposed to have, a biological thermostat for body weight, on one of three competing models. On that model, losing weight raises hunger and lowers energy expenditure to push weight back up. Research by Fothergill on Biggest Loser contestants showed metabolic suppression persisting 6 years after weight loss. Rosenbaum and Leibel documented adaptive thermogenesis in humans. This companion covers the biological thermostat, how the lipostat defends against weight loss, the asymmetry problem, whether the set point can change, implications, and working with the lipostat. (5 min read)

The body may compensate for exercise calories through hunger, reward eating, less movement elsewhere, and efficiency. Pontzer’s 2016 study found that above moderate activity levels, total daily energy expenditure plateaus, because the body compensates for additional exercise. How much is compensated varies enormously between people, and approaches 84% over about eighty weeks. This companion covers compensation mechanisms, the research reality, why this matters, the “outrun your diet” myth, what exercise actually does, and the practical approach. (4 min read)

The fed-to-fasted transition is usually presented in five stages: fed (0-4 hours), early fasting on liver glycogen (6-24 hours), gluconeogenesis (24-48 hours), ketosis (one to three days), and protein conservation (five days and beyond). That framing is Jason Fung’s presentation of mainstream physiology rather than a measurement: the phases are real and the tidiness is editorial, with the boundaries overlapping and blurring. Understanding them removes mystery from fasting; treating the hours as thresholds you cross on a schedule puts it back. This companion covers each stage in detail, what’s happening hormonally, how it feels, why this matters, and practical implications…

Your body maintains blood sugar during fasting through multiple mechanisms: the liver releases stored glucose (glycogenolysis), produces new glucose from non-carbohydrate sources (gluconeogenesis), and hormones like glucagon and cortisol regulate the process. Research by Cahill documented how humans remain functional through extended fasts because the body has reliable systems to maintain glucose without eating. Blood sugar doesn’t crash: it’s carefully maintained. This companion covers the fear versus reality, the three mechanisms (glycogenolysis, gluconeogenesis, ketone adaptation), hormonal regulation, what “low blood sugar” actually means, and the irony of frequent eating. (5 min read)

Insulin sensitivity means your cells respond efficiently to insulin, so a small amount effectively moves glucose into cells. Insulin resistance means more and more insulin is required to do the same job. You want sensitivity. In a small isocaloric trial of eight overweight men with prediabetes, eating earlier in the day improved insulin sensitivity without weight loss, which separates timing from calories; it is the right kind of evidence at a size that cannot prove anything on its own. Resistance is a step toward type 2 diabetes; that it also drives fat storage and hunger is the carbohydrate-insulin model’s proposal,…

Adrenaline (epinephrine) increases during fasting. Resting energy expenditure rises rather than falls in short-term fasting: about 14% over three days in one small study, though the larger study puts it at 6% by 36 hours, gone by 72, and absent in men. The tempting explanation, that catecholamines drive it, is one that study’s own authors decline: metabolic rate peaks when noradrenaline has not yet moved. This is the body mobilizing energy stores, signaling fat cells to release fatty acids. What none of it establishes is how fasting feels; a review argues that alertness while foraging would have been adaptive, but…

Whole foods tend to leave you satisfied and ready to stop. Processed foods behave differently, with satisfaction delayed or incomplete, though the imaging behind it set processed food against a tasteless control rather than against whole food, so it yields no comparison of size between the two. The difference the research does define is composition: fat with sodium, fat with sugar, or carbohydrate with sodium, each above a set threshold. A 2019 inpatient trial showed people on an ultra-processed diet took in 508 more calories a day than on a nutrient-matched unprocessed one, while rating both equally pleasant; faster eating…

The hypothalamus is the brain’s weight regulation center, a small region that integrates signals from hormones (insulin, leptin, ghrelin), nutrients, and the nervous system to control hunger, satiety, and energy expenditure. Research by Fothergill on Biggest Loser contestants showed metabolic rates suppressed by hundreds of calories daily, even years after dieting. On the set point model, one of three and not the settled one, the hypothalamus defends a weight range against loss through increased hunger and decreased metabolism. This companion covers the command center’s key players, hormonal inputs, set point defense, how the set point can change, and why hormonal…