What Really Happens To Your Body (And Brain) On A Detox Diet?
Want to sign up for a full-on juice detox? You might first want to consider how your body reacts to a week with no protein and less than 4 000kJ a day

July 14, 2015

By Laura Beil; Photography by PIxabay

To juice or not to juice… that is the question

Thinking of signing up for a juice detox? You might first want to consider how your body reacts to a week with no protein or fat and less than 4 000kJ a day.

After the first sip

Your brain’s hunger signals are answered with a dump of pure fruit-juice sugar. And don’t get any ideas – veggie-based cleanses aren’t any healthier. The sweet stuff prompts the pancreas to squirt out insulin, which moves sugar – now in your blood in the form of glucose – into your cells.

After 30 minutes

As your cells suck up the glucose, your blood sugar level can start to plummet and you may feel dizzy. Meanwhile, lacking enough kilojoules, your body is operating off its supply of glycogen, a form of short-term energy stored in the liver and muscles.

After two days

With each shot of juice, your insulin levels skyrocket, then crash. At this point, your glycogen stores are pretty much gone, leaving your tank on empty – and you feeling listless.

READ MORE: Are Detox Diets And Cleanses Really Good For You?

Since you’re getting about half the kilojoules you need, your body draws on long-term power sources: triglycerides, a type of energy stored in fat cells (woo-hoo!), and protein, taken straight from your muscles (oops). You begin to lose muscle mass, even if you’re still exercising every day.

After three days

Your brain is not happy. It enters into semi-starvation mode and gobbles ketones, fuel that comes from the breakdown of fat. Ketones work, but they’re like watered-down petrol; as a result, you may feel unfocused or irritable. (Any “mental clarity” is likely due to a strong placebo effect.)

Sans a fresh protein infusion, your brain is also lacking amino acids, the raw materials that neurotransmitters need to maintain your mood. If you’re prone to depression, you may start feeling blue.

READ MORE: 3 Things To Know Before You Go On A Juice Cleanse

The proteins in your shrinking muscles break down into ammonia and uric acid, unwelcome chemicals that invade your bloodstream. Now your kidneys are busy detoxing your detox.

Stay near the bathroom: the juice’s high carbohydrate load causes a surfeit of water to enter the intestines. That extra H2O in your gut means you’re primed to get diarrhoea.

After four days

With no food to digest, your small intestine feels ignored. Its villi – the rows of tiny fibres that move food elements into the blood – start to atrophy. Your diarrhoea may get worse, leading to dehydration… and there goes your rosy glow.

On the eighth day

Solid food! But uh-oh – you’ve lost muscle. Even if you go back to your regular eating habits, you now have less muscle mass to burn those kilojoules; instead, the kilojoules are more likely to be turned into fat. (Hence, one reason yo-yo dieting makes it harder to lose weight: your reduced muscle-to-fat ratio messes up your metabolism and makes kilojoules much harder to work off.)

Looking for more info on cleanses? Why not reboot your system the healthy way and download this 5 day healthy eating plan instead.