Ged Cann talks with clinical nutritionist Sonja Gardiner.
As I embarked on my weight-gaining mission, I have learnt one hard lesson: changing your diet is hard.
As someone who has never had to worry about their weight, I always thought it was just a case of eat more, eat less, or simply eat different.
However, whatever option or combination of the three you choose, there will be complications and difficulties you never expected.
My first month of eating 50 per cent fats, 25 per cent protein and 25 per cent carbs in pursuit of gaining weight was a real struggle.
You have to discover new foods, increase your intake from sources that were previously only supplementary, and with every change comes a fresh demand on your body to adapt.
Some things your body adapts to quickly, others give you problems.
Take for example, legumes - chickpeas, beans, lentils and soy beans. Before my diet change these were relatively limited to hummus, soy milk in my coffee, and the occasional dhal curry.
Now I had to turn to these in order to top up my protein (I was still determined to remain primarily vegetarian) but as it transpires these are also the worst culprit for FODMAPs which contribute to IBS.
FODMAPs and IBS? FODMAPs are carbohydrate chains and IBS is irritable bowel syndrome.
To put it bluntly, large consumption of legumes resulted in me having more upset stomachs than the All Blacks at the 1995 Rugby World Cup in South Africa.
FODMAPs that might affect a person can come from excess fructose (from certain fruits), lactose (milk and dairy), fructans (certain vegetables, cereals and fruit) galactans (legumes) or polyols (some fruit, vege and sweeteners).
According to my nutritionist Sonja Gardiner, it is difficult to identify which affects a person because there is an 18-hour delay before the food reaches the large intestine and starts causing trouble.
This makes it harder to identify the offending food group than it is to identify the mystery meat in a petrol station pie.
It's a long-haul process of elimination to discover which affects an individual.
Then there were the instructions I had received from Sonja - to have a teaspoon of apple cider vinegar before every meal.
To me this sounded like a bit of a wind-up, like when I told a friend in college that sprinkling sugar on your underarms was an effective deodorant.
But Sonja was serious, and assured me it would help with my "digestive fire" - something I was apparently lacking due to my vegetarian tendencies.
I gave it a go, and if I'm honest it went down about as well as a beef stew at a Hindu wedding.
I think if you're going to do any new diet properly you inevitably end up with a few pent-up emotions towards your nutritionist. Whether they are refusing you your favourite snack or forcing you to drink vinegar, the greater the adherence the greater the anger.
In all honestly however, Sonja was incredibly supportive and knowledgeable, and given my weight gain of 2kg in three weeks she must know what she's doing.
Sonja Gardiner is a Hamilton clinical nutritionist on a mission to bring health, wholeness and happiness back into people's lives. For more information see www.sonjagardiner.com