Like thousands of other women, Donna Parker and Eileen Geddes decided at the beginning of the year that they wanted to lose weight.

Donna, who was 23 stone, wanted a healthier lifestyle; Eileen, who was 16 stone, wanted to get slimmer for her son's wedding in September.

For the six weeks that followed, Herald Woman followed both of the women as they set out on their new regimes. Donna, from Glasgow, joined WeightWatchers while Eileen, from Airdrie, joined a gym and followed a low-GI diet.

Although there were times when both Donna and Eileen struggled, over the six weeks their weight started to come down. Donna noticed her dress sizes dropping and Eileen – much to her own surprise – learned that she loved running.

Eight months after that promising start, how are the women getting on and what lessons have they learned about losing weight in the middle years of life, when weight can start creeping on? The news is good. Donna has lost 3.4st (47lbs) and Eileen 5st. Not only that: they have changed what they eat, how they eat and how they live.

"It was the age thing," says Donna. "When you're younger and you're in your teens or your twenties, you think: 'I'll do it next week' but for me it was now or never."

Donna found the structure of a points system a big help, and she now knows the points value of many foods without looking them up. That's the aim of WeightWatchers: to eventually get you off the points and eating healthily.

She also discovered little tricks to lose weight while also satisfying her sweet tooth. Popcorn, for example, instead of chocolate or crisps; roasted peppers instead of chips; and grating cheese instead of slicing. She also grills vegetables that in the old days she would have fried.

As for losing more weight, Donna's target is still the same: she would like to get down to 15st. And as she makes her way towards that, she's discovered a pleasant side effect of losing weight. "I'm happier," she says. "I enjoy getting up in the morning."

Eileen feels much the same and is particularly delighted that she has achieved her target of getting into a size-14 dress for her son's wedding (in January, she was size 18).

Like Donna, Eileen has allowed herself the odd treat – in her case, a curry – but has kept the focus on low-GI foods. "I don't see this as a diet as such. I see it as learning what you can eat. Your mind has to change and then you get hooked on it."

The great revelation for Eileen has been that she enjoys the exercise; earlier this year, she did her first 5K. "I really enjoy the running and the camaraderie of running with other women from the gym," she says. Eileen believes having friends around you makes things easier.

Donna agrees with that; she is friends with the other WeightWatchers members on Facebook, where they offer each other support. "We all struggle day to day," says Donna, "but now we can help each other."