Mandy Allan (49) of Ormiston in East Lothian has set her sights on completing the River Ness 5K – part of the Baxters Loch Ness Marathon and Festival of Running – to raise money for Marie Curie, after losing family members to cancer

Last year my mum passed away at the age of 70 from tongue cancer at the Marie Curie hospice in Edinburgh.

Her death followed my fathers who died from lung cancer and my grandmother’s from throat cancer – all of which were linked to smoking

In memory of them 2017 will be the year I change my life. I’m fed up with being overweight and unfit. I have gave up cigarettes, started to eat healthily and begun exercising.

I’ve followed fad diets for years and after losing a bit of weight I’ve put it all back on. I currently weigh just under 17 stones. I’ve never been heavier than I am now, and I am so unfit it is frightening.

I’ll be 50 this year and I’ve decided that enough is enough. I want to see my grandchildren grow up into teenagers and then adults, and unless I do something to change my lifestyle I worry that it is not going to happen.

Losing my mum has been so hard but I promised her before she died that I would change and that I would raise money for Marie Curie while doing it.

I’m not going back on that promise so have signed up to take part in the River Ness 5K this year

Last year my son Daniel (26) completed the Baxters Loch Ness Marathon and he has inspired me and developed a training and nutrition plan that will help me shed the pounds and ensure I cross the finish line in Inverness on 24 September.

He’s always been fit and healthy, but got into marathon running two years ago with a workmate. We call him Forrest – as in Forrest Gump – because he’s always running.

I will never forget the atmosphere as I waited for him at the finish line last year; it was so emotional and there was such a buzz of energy.

He came up and gave me a hug and said, "that was for Nana". It reminded me of the promise that I had made to her, and I decided there and then that I would be taking part in 2017.

I may not be running the full marathon distance, but I can’t run the length of myself at the moment so, for me, completing the 5K will be just as big an achievement.

Daniel is taking me out walking several times a week, slowly building up to very short periods jogging and ultimately working towards running the entire 5K distance. He bought me a FitBit for Christmas so I track my activity levels and calorie intake.

My other sons Fraser (31) and Jordan (21), as well as my husband, Arthur (50) are also supporting me. Arthur has pledged to give up smoking with me and he has no choice about eating more healthy foods too as I do the cooking.

I haven’t set a target for how much I want to raise for Marie Curie, but hopefully a few hundred pounds. If I had a million pounds in my pocket right now, I would give it all to them.

The nurses and staff made my mum so comfortable in her final days and made the family feel so welcome. It was nothing like I thought a hospice would be – it was almost like going to a hotel where they staff couldn’t do enough for you.

The Baxters Loch Ness Marathon and Festival of Running was launched 16 years ago. The main charity partner is Macmillan Cancer Support, but there are numerous affiliate charities associated with the event. In addition to the 26.2-mile course, the Festival includes the River Ness 10K, 10K Corporate Challenge, River Ness 5K and the Wee Nessie fun run for pre-school children. Entries for all races are available online now at lochnessmarathon.com.