‘PLEASE TELL ME ABOUT THE ROLES OF GHRELIN AND LEPTIN’
'Why is there so much talk about replacing salt on an LCHF diet?'
Sally-Ann Creed answers this and other reader questions
Q: Please tell me about the roles of ghrelin and leptin. A: Ghrelin and leptin are your hunger hormones. They switch your hunger and satiety levels on and off. Ghrelin signals hunger, leptin signals fullness.
When it comes to losing weight you are at their mercy. When ghrelin has the upper hand and its level rises you begin to feel hungry so you eat. Once your body’s need for nourishment is taken care of leptin begins to rise, ghrelin drops and your hunger dissipates as your feeling of fullness takes over. Sounds simple enough – but not so fast. You might find it interesting to know that if you restrict your food intake too much your ghrelin level increases and your leptin level drops. In other words you will always feel hungry. This is why sane weight loss is so important: you don’t want to mess up your hormones – especially your delicate thyroid hormones and, of course, leptin and ghrelin. Messing around with these hormones sets you up for future misery as they are not easy to fix. The moment you let your guard down you will put on weight again. It’s perverse. Therefore take heed as to how you treat your precious body and its hormones.
Here’s what to do to protect these hormones while still losing weight: 1. Get plenty of sleep. Those who sleep enough have been shown to have higher leptin and lower ghrelin levels than those who don’t get adequate sleep. If you have a night without sleep you will generally be hungrier the next day – not for healthy food but for carbohydrate-rich food. Add a mere 20 minutes of sleep to your night and you may find the kilos dropping off a little faster. 2. Avoid fructose. It causes ghrelin to rise, which is why you are hungry half an hour after eating fruit. Fructose is in a lot of food as a so-called ‘sugar-free’ sweetener. Agave is one of the worst offenders as it is almost all fructose. Avoid it like the plague. 3. Don’t try to lose weight too fast. This always ends in misery! A steep drop in food intake has a terrible effect on your metabolism and is likely to increase the release of ghrelin, which is not what you are looking for. As your body adjusts so your metabolism slows down to accommodate this but when you eat more your body doesn’t readjust – you simply put on weight. You do need to avoid refined food and a high-carb diet but don’t be foolish and go too low carb or reduce your food intake too much, too quickly. Be level-headed about weight loss. Take your time and learn to eat real food in appropriate portions. By doing this you will remain friends with both ghrelin and leptin.
Q: Why is there so much talk about replacing salt on an LCHF diet? A: When you have fewer carbohydrates in your diet your body loses water and, with it, sodium. Sodium is a crucial mineral for our bodies; like cholesterol, it is essential if we wish to remain alive. When your insulin is high your body tells your kidneys to hang onto sodium but on an LCHF diet the carbs are reduced, more water is lost and more sodium is excreted. Since it is such a critical electrolyte, reduced sodium levels can lead to cramps, fatigue, lightheadedness, and even constipation. There’s an easy remedy here, however: simply add more high-quality salt to your diet. Don’t be concerned about hypertension: if you have normal blood pressure then extra salt in an LCHF diet won’t predispose you to hypertension.
Q: One word: alcohol. A: Yes, this is a one-word question… and another one I’m constantly being asked. You need to know this: it’s about much more than just the carbs! Alcohol has its own agenda when you are trying to lose weight. There are those who can successfully lose weight on regular alcohol intake but for most people, women especially, it is a death knell to weight loss.
Fat metabolism drops by more than 70% if you consume alcohol. A drink prevents fat loss from the existing body stores while stashing away more and, chaps, it drops testosterone dramatically – so if you are trying to start a family and still enjoying a beer at every opportunity this may be why your wife is not conceiving.
Alcohol raises the level of cortisol, which causes muscle wasting and fat deposition, while reducing testosterone for up to 24 hours after the last drink. For both men and women alcohol reduces the ability to build strong fat-burning muscle as the effect on muscle is catabolic. Alcohol also slows down metabolic rate.
Acetate is produced from alcohol and once that’s in the bloodstream the body prefers to use this for energy instead of fat. Plus, the more you drink the more you want to eat – alcohol gives you the munchies – and in the process, the body turns the acetate into stored body fat.
One last thing: your oestrogen level increases by up to 300% so while you’re ‘just’ enjoying a drink your testosterone is plummeting, your oestrogen is soaring and your waistline is expanding, to say nothing of what it’s doing to the brain, heart and blood viscosity.
Dehydration is a common problem in the regular drinker too and the kidneys have to rally if the body is dehydrated. For body fat to be metabolised it needs to be released by the liver but dehydration causes the liver to neglect those duties in favour of coming to the aid of the kidneys. Alcohol causes fat to be stored in the liver (hence fatty liver disease) and after a while actually impairs the liver’s ability to cope, which results in a damaged liver. Your liver is your greatest ally when it comes to weight loss and overall good health. It performs more than 400 functions – it’s extremely important.
Sodium is a crucial mineral for our bodies; like cholesterol, it is essential if we wish to remain alive.