Leptin and Ghrelin: How to Stop Fighting Your Hunger Hormones
Leptin says you have enough. Ghrelin says you need more. When the pattern of your week distorts both signals, no amount of discipline wins the argument.
Most people believe body weight is a maths problem solved by self-control. It is closer to a thermostat, and the thermostat has two main dials. Leptin tells your brain there is enough energy on board. Ghrelin tells it to go find some. When those signals are distorted, discipline is arguing with a system built over a few hundred thousand years to win.
The Two Signals, Plainly
Ghrelin is produced mostly in the stomach and rises before your habitual meal times. It is the growl, the distraction, the reason a granola bar starts looking like a plan. It falls after eating, and it falls furthest after meals containing protein.
Leptin is produced by fat tissue and reports back on stored energy. More stored energy means more leptin, which should mean less hunger. That is the theory. In practice, chronically high levels make the brain progressively less responsive, which is what people mean by leptin resistance: the message is being sent and nobody is picking up.
What Distorts the Signals
Short sleep
This is the fastest lever in either direction. Restrict sleep to four or five hours and the next day brings measurably higher ghrelin, lower leptin, and a documented pull toward calorie-dense food. One bad night is survivable. A permanent pattern of six hours makes fat loss feel like a fight you keep losing, because it is.
Chronic stress
Sustained cortisol elevation increases appetite and preferentially drives cravings for sugar and fat. In Vancouver terms, a stacked work quarter and a 6am commute do more damage to your food choices than any single meal ever will. Our piece on cortisol triggers covers what to actually change.
Ultra-processed food
Hyper-palatable food is engineered to bypass satiety. It is calorie dense, low in fibre, low in protein, and fast to eat, which means the fullness signal arrives after the food is gone. The problem is not moral, it is mechanical.
Aggressive restriction
Big rapid deficits drop leptin quickly, and the appetite response that follows is why the last two weeks of a crash diet are the hardest and the four weeks after it are worse. The people who keep the result are almost always the ones who lost it slowly. See the restart cycle mistakes for the pattern.
The Five Things That Actually Help
- Sleep seven to nine hours, on a consistent schedule. Nothing else on this list works as well while this one is broken.
- Front-load protein. Thirty to forty grams at the first meal flattens the hunger curve for hours. This is the single most reliable change we make with coaching clients.
- Eat fibre with every meal. Volume and slower gastric emptying do real work on satiety. Vegetables, legumes, whole fruit.
- Lift heavy twice a week. Strength training improves insulin sensitivity, which sits upstream of how well these signals land, and it protects lean mass during a deficit.
- Make the deficit boring. A small, sustainable gap that you keep for six months beats a dramatic one you abandon in three weeks.
What This Looks Like on a Tuesday
Wake at a consistent time. Eggs, Greek yogurt or a protein shake with fruit inside the first hour you are hungry. A real lunch with protein and vegetables rather than a snack-based grazing pattern. Train in the late afternoon or evening. Eat a dinner you actually like. Stop eating late enough before bed that you sleep well, and go to bed at the same time you did yesterday.
It is unglamorous, and it works, because it stops asking willpower to do a job that biology was always going to win.
If you want a coach to build this around your actual schedule rather than an ideal one, that is what we sort out in a movement assessment at our Olympic Village gym.
A 2026 original rewrite of a topic first covered on Dai Manuel's archive. Coaching guidance, not medical advice.