About three months ago I was browsing on Twitter one aimless evening when I came upon an intriguing message on the page of Lord McConnell, Scotland's former first minister.

His words, roughly, were thus: "I'm going to live on £1 a day for food and drink for 5 days in the fight against poverty - care to join me?"

I'd obviously had a little too much beer that night because, for some reason, my finger reached for the reply button and I typed: "Tell me more, Jack."

It was the trigger for me joining him and thousands more across the world in Living Below The Line for five days of the past week.

The rule was, you spend no more than £5 on all food and drink in advance, and your cache is to do you for five days. I finished my stint at the weekend and, I can tell you, it meant going to bed for five nights feeling pretty peckish as the lights went out.

There is an obvious cynicism about comfortable, middle-class blokes "playing at being poor" and indulging in this sort of thing - I get all of that and have expressed such cynicism myself on occasion.

On the other hand, I've come to deeply admire the fight against poverty, both at home and abroad, by people like Jack McConnell, church groups, schools, and all sorts of others. Poverty is probably the only public issue that makes my blood boil. It is a disgusting reality here in 2014.

I joined the Live Below The Line campaign last week for two simple reasons. First, I believed in my own minor way that I could highlight the scourge of poverty once more - nope, it wouldn't make me unique, or a saint, but it might help.

Second, I hoped to raise around £1000 or more - which I did - to alleviate the problem. £1000…it's hardly world-changing, right? But it was something.

So off I toddled to the local supermarket last Saturday night, five pound coins in my pocket, to get my stuff in. It's dog-eat-dog, this, so you fight for anything you can get for a fiver: the basics ranges, the deals, the low-grade coffee that tastes like tar (I got a bag for 50p) and the like.

I bought two tins of beans for 22p each. I bought a bag of spaghetti for 20p. Usually, marauding up and down the supermarket aisles with tenners falling out my pockets, I scarcely stop to blink at the prices. I mean, spaghetti, for 20p?

I bought (all cheap and basic): porridge, bananas, sausage rolls, a tomato sauce (disgusting stuff), chocolate biscuits, milk and a clove of garlic. Total price for five days of grub: £4.98.

Day One was fine. I got wired into my watery porridge for breakfast, sausage rolls and beans for lunch, and spaghetti with the nauseating sauce at night, and I thought: "You know what…I'm up for this."

To boot, I even had my cheap, nasty coffee to go with it - it's perfectly drinkable stuff - and really felt I could cope comfortably.

But then the reality hit home on Day Two and Day Three. The same stuff over and over: same breakfast, same lunch, same dinner.

By Wednesday I almost couldn't bear to look at my motley collection of sausage rolls, neatly laid out in the fridge for each day, with their unconvincing mix of meat and sawdust for a filling.

By Thursday my routine evening meal was becoming detestable: the sickly repetition of spaghetti with that vinegary sauce.

What made it all worse was the gorgeous, wafting smells of the other traditional cooking going on around me in our house.

Originally, we were going to do "Live Below The Line" together as a family, but my wife wisely decided that it would be too difficult to fix, with our three children all under six and requiring different dietary needs here, there and everywhere.

So I had to look on, stuffing gruel into my mouth, as everyone around me fed themselves on homemade soups (wow, the smell of that!), stews, chicken casseroles, fish-pies, freshly-cut fruit and the rest.

On one of the nights a sweet-smelling apple pie emerged from the oven. On occasion, as I sat lurched over my plate, my wife would say: "Pour me a red, would you?"

The lovely porridge aside, with all this "food-cardboard" going over my throat, the thing I really craved most was fruit. When my five days were done, just to have that fresh, sweet, citrusy texture in my mouth, was heaven itself.

I don't mind saying it - I also missed my beer. I'm not a big drinker but, by God, I've lovingly quaffed and guzzled a few bottles since my fast was done.

In more ways than one, it has been a sobering exercise. Food hunger must be extremely painful, yet here in Scotland many people actually confront this on a daily basis. We have children in Scotland - can you believe this? - who go to bed at night feeling hungry.

Our nation is rich - it is abundant, actually - yet our society still cannot take 20% of its children out of poverty or food deprivation. I absolutely detest this truth.

I've not minded being a do-gooder for a week. Nope…not minded the teasing, the barbs, the "it's alright for you, Jack" put-downs as I have publicised the campaign.

It has been well worth it. It has revealed some painful home truths.