Tag: Knowledge recall

Growth hormone rises steeply during fasting: production rate up five-fold by day two of a fast in normal men, and integrated concentration up from 2.82 to 8.75 µg·min/ml in six men, most of that rise already there by the first fasted day. Whether that rise spares muscle is not shown: the one direct test did not find protein sparing over a 36-hour fast. Nor does fasting beat dieting for muscle: Trepanowski’s 2018 trial found no significant difference between them. This companion covers what growth hormone does, the fasting effect on GH secretion, why this matters for muscle preservation, and practical…

Calorie-dense foods pack many calories into small volumes; nutrient-dense foods deliver high nutrition relative to calories. Rolls’s volumetrics work describes people eating a fairly consistent weight of food, so lowering calorie density tends to mean more volume for fewer calories. On typical food-table values, non-starchy vegetables run 0.1-0.5 calories per gram; oils are 9. The ideal: high nutrient density, low calorie density. This companion covers both concepts, why calorie density matters, the optimal combination, and practical application for building meals. (4 min read)

Leptin is the satiety hormone, released by fat cells to tell the brain “we have enough energy stored.” Research by Friedman discovered leptin in 1994, but subsequent studies found that people with obesity often have high leptin levels: the usual account is leptin resistance, where the brain doesn’t hear the signal, though whether resistance causes obesity or follows from it is debated. More leptin is not the fix. This companion covers leptin’s intended function, the resistance problem, what causes it, and how to address it. (4 min read)

The protein leverage hypothesis proposes that humans have a strong drive to consume specific protein amounts. Simpson and Raubenheimer propose that if protein is diluted by carbs and fats, we overeat total calories to hit our protein target. A drop from 15% to 10% of dietary calories from protein can increase intake by 12%. Modern processed foods are typically low in protein relative to their calories, which on the hypothesis leaves the target unmet. This companion covers the discovery, human evidence, why protein is defended, the processed food problem, and practical implications. (4 min read)

At 12 hours you are leaving the fed state; by 24 you are in the fasted one. The switch between them is usually placed somewhere in a 12-to-36-hour window rather than at a milestone, and where you land in it depends on your glycogen and your activity. This companion walks the windows, says where the research gives ranges rather than hours and where the round numbers come from nowhere, and covers individual variation and matching fasting durations to your goals. (5 min read)

Your body appears to defend a particular weight range with surprising persistence. Research by Leibel and Rosenbaum shows that when you lose weight, metabolic rate drops, hunger hormones increase, and energy expenditure decreases, all pushing you back toward previous weight. The “Biggest Loser” study found persistent metabolic suppression six years later. You’re not fighting just habits; you’re fighting physiology. What that physiology is defending is the part still argued over: set point is one model, settling point is another, and neither pure model is adequate alone. This companion covers the competing models, the evidence for weight defense, why the responses…

When animals are given access to a variety of highly palatable foods rather than standard chow, they overeat and become obese. The cafeteria-diet experiments of the 1970s are the animal half of this; the human half is Rolls’s work on sensory-specific satiety, where the pleasantness of a food falls as you eat it while untouched foods stay appealing, so variety keeps appetite going after need is met. The modern food environment is a giant cafeteria diet experiment: endless variety and highly palatable food, on this page’s view. This companion explores the original cafeteria experiments, why variety drives overconsumption (sensory-specific satiety),…

Ghrelin is the “hunger hormone” that rises before your usual meal times, not because you’re running low on energy, but because your body expects food. Cummings’s 2001 study showed ghrelin peaks preprandially, before meals, with its own paper putting it as suggesting a role in meal initiation. Over longer spans ghrelin does track energy state, rising with weight loss. Crucially, ghrelin comes in waves: in one small fasting study it spiked, peaked, then receded on its own within about two hours. Whether the hunger follows it down was not measured there. This companion covers ghrelin’s role, the meal-time schedule, hunger…

Four qualities are associated with lasting satisfaction without overconsumption: high protein, high fiber, high water content, and low caloric density. Research measuring 38 foods found boiled potatoes scored 323% on the satiety index while croissants scored just 47%. Fat, surprisingly, had a negative correlation with fullness per calorie. This companion explores the satiety index, the four factors that predict fullness, why this explains which eating patterns work, and how to choose foods that satisfy naturally. (4 min read)

Protein raises insulin too, but differently than carbohydrates: eaten alone, it keeps blood sugar stable while insulin rises. Holt’s insulin index found protein-rich foods drew insulin responses disproportionately higher than their blood-sugar responses. Protein also triggers glucagon, which partially offsets insulin’s effects. Eaten with carbohydrate, protein draws more insulin than either alone. This companion covers carbs and insulin, protein and insulin, fat and insulin, and practical implications for meal design. (3 min read)