Matt Hodges reflects on the pleasure and pain of a recent seven-day water fast.

"So how much weight did you lose?"

That was the first question I got in response to my seven-day water fast, which I capped with a "buffer" day that allowed for one carton of fresh orange juice.

I did not weigh myself afterwards, so I don't know. But I shed plenty of fat, dangerously quickly, which left my ribs poking through my skin and resulted in a temporary six-pack.

I also kissed goodbye to a fair bit of muscle. Within two weeks, all the belly flab had returned - with a vengeance. I'm still working on getting my guns back.

Fasting to lose weight is pointless, painful and potentially dangerous. Your body naturally restores equilibrium too quickly. You should also consult with a physician before going down this road. Maybe I was lucky to come out the other end unscathed. But I feel like most people could handle it.

In my case, the end result was positive. It didn't clear up those nagging food allergies, but my stomach was more settled, my stool smoother, the brain fog lifted. I just felt better. I don't have a medical explanation.

It makes sense to give your digestive system a vacation as the process of breaking down food is massively draining on the body's energy resources.

Some scientists argue that, once freed of this chore, the body reverts to auto-clean-up mode after a few days, deleting damaged or delinquent cells in much the same way that an anti-virus program gets rid of the uninvited guests on your hard drive.

I did the fast due to gastro-intestinal problems that no doctor has been able to identify, but which have left me allergic to foods containing wheat, flour or yeast (still not sure which). Celiac and gluten allergy tests came back negative, as did every other test result.

It eventually became apparent that a diagnosis of "gastritis" or "irritable bowel syndrome" is medical speak for "we have no clue what's wrong with you".

Frustrated with all the antacids, proton pump inhibitors, antibiotics and other ineffective band-aids being prescribed, I went on a gluten-free diet, then sought out more radical "solutions".

What surprised me about going eight days without food is that I never felt hungry. Hot water plugs the gap. Boredom is the real killer.

Day two was a giant headache, literally, but the migraines cleared up on day three—just in time for inertia and listlessness to set in. Even climbing stairs will leave you breathless as your body goes into ketosis.

By day five I was so low on energy I could barely speak. The next day my energy levels magically replenished themselves. By day seven, I knew I could maintain the fast for 10 days if I wanted, but I worried about the health implications. Thoughts of food were monopolizing my waking hours, even though I wasn't technically hungry.

You can't just dive back into a regular diet afterwards, so expect a couple more days of consuming fruit, fruit juice and porridge.

It takes a lot of mental discipline to see a fast through, if there were no health or spiritual benefits, why would it form a core part of so many religious practice and why would so many secular types proselytize about its usefulness?

Even my grandma, when asked how she was able to attend keep-fit classes in her early 80s, attributed those lean years of living through the Blitz, when Londoners had to survive on paltry food rations, as the secret to her longevity.

You definitely learn a lot about your body, what it is capable of, and what it needs. I achieved a kind of mental clarity and realized that I chronically overeat, and that I don't need caffeine, to survive the working week.