Have you ever wondered why losing weight isn’t always as simple as “calories in vs calories out”? On a biological level, it really is a case of maths (if you expend more calories than you take in, you’ll lose weight). But we are humans, not robots, so we must think about the behavioural aspect of dieting, too.
Why losing weight isn’t just about calories
The calorie equation only works if you actually hit the required numbers. And, as every dieter knows, that feels pretty easy some days. Other days, not so much.
What’s driving those hungry, bottomless-pit days where you just can’t seem to stop thinking about food? And what’s different on the days where you really don’t feel hungry at all? Let’s look at the science of the two key hunger hormones: leptin and ghrelin.
What do hormones have to do with appetite?
The human body is governed by the endocrine system, a sophisticated network of glands that release hormones. These hormones are chemical messengers that send signals around your body telling it what to do. Everything is governed by hormones – including your appetite, hunger, and fullness.
Isn’t losing weight down to willpower?
Whilst willpower and forward-planning can certainly help you lose weight, that’s not all there is to it. And if you adopt such a strict and reductive viewpoint to appetite control, you can expect to feel disappointed. That’s why it’s really important to understand the role of leptin and ghrelin, and how to manage them to make weight loss easier.
Leptin, the fullness hormone
The hormone leptin tells your brain when you’ve had enough to eat. It’s produced by fat cells – you actually have more leptin in your system if you have more subcutaneous body fat. Leptin is responsible for telling you to stop eating because you’ve had enough (or already have enough stored energy aka fat). But it’s also involved in immune health and even the reproductive system.
A small number of people are leptin-resistant, which means their brains don’t recognise even very high levels of leptin and therefore they will continue to eat and eat even when they’re full (and/or very obese).
Ghrelin, the hunger hormone
Ghrelin prompts you to eat by causing hunger pangs, sending signals to your brain to say “it’s time to eat!” Ghrelin is produced mainly in the stomach (with small amounts released from the brain and small intestine).
Ghrelin’s main tole is stimulating appetite, but it also plays a part in sleep, taste, and regulating glucose and insulin.
Your levels of ghrelin will naturally rise and fall during the day as you eat. When your stomach is empty, ghrelin travels through the bloodstream to the hypothalamus in the brain, which kicks off the signalling process to eat.
Why we should be grateful for ghrelin and leptin
The body is an amazingly clever system. Ghrelin and leptin work as a partnership to keep you fed and energised, but not overfed or too fat. We do have to learn to listen to them, though!
This can be a challenge in our modern environment of food delivery apps, food adverts, and product placement.
5 ways to manage your hunger hormones
1. Get enough sleep – 7+ hours sleep a night helps your hunger hormones work properly. If you don’t get enough sleep, you’ll have less leptin and more ghrelin, which will make it difficult to know when to stop eating
2. Eat enough protein – protein is a very filling macronutrient which helps you control your appetite. Eat 20g+ protein with every meal, even breakfast.
3. Eat regularly – research tells us (1) that restrictive diets and fasting can cause levels of ghrelin to rise, which may lead to overeating or even bingeing.
4. Mindful eating – leptin can only help you if you slow down enough to listen to it. Practice mindful eating, which means no screens or phones. Concentrate on your food and eat slowly.
5. Sustainable diet methods – ghrelin may explain why harsh diets and very low calories usually lead to weight regain. Make sure your weight loss diet is reasonable and sustainable.
Have you always struggled with hunger or weight regain on previous diets? Let me help you with a sustainable weight loss plan that you can stick to as a lifestyle change.
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