Hopefully we all know by now that new year's health resolutions are a waste of time.

Very often, those lofty goals we set for ourselves - get fit; run a marathon; lose 5kg - are in tatters by the time March rolls around.

"The whole New Year's thing ends up with: 'Oh my gosh, I've failed. I'm hopeless'," says behavioural researcher Fiona Crichton.

"What I've learned is: we are setting ourselves up for failure…we are saying, 'we've gotta do all this big stuff'.

"And nobody can do big stuff.

"We have a tendency to be very, very hard on ourselves.

"And what happens is that it impacts mood.

"It impacts self-efficacy.

"It impacts your ability to pick up new habits."

So what to do if you're feeling motivated to make changes and you want them to stick?

Here are five habits to work on this year that experts say will definitely mean you're healthier in body and mind by the time 2025 rolls around.

Stop drinking (or cut right down)

Almost all Kiwis drink alcohol - the latest Health Survey found 76 per cent of us said we'd had a drink in the last month.

It's a slight trend down from our heavy-drinking lockdown years.

It's not news that alcohol is bad for health in many and varied ways; from being known to cause at least seven types of cancer to being implicated in sleep issues, mental health disorders and general risk of injury or death.

Drinking very little or nothing is the strategy every health expert agrees on.

What do you do if you want to cut back - or become a non-drinker?

Fiona says small tweaks to our routines can help form new non-drinking habits (assuming there is no issue with addiction).

"The thing about alcohol is that there's craving, and we have triggers.

"So, if you are used to coming home and having a drink, you'll walk through the door and you'll want a drink.

"We have conditioned responses.

"Our brain is going, 'you're going to get the dopamine and you'll feel better'."

She suggests following the same routine but swapping out the drink.

"So I'll go to the fridge; same routine - but instead I'll have a [non-alcoholic] soda.

"And honestly then I don't want the vodka, even though I think I will.

"Sometimes it's not taking things away, it's just making the routine the same as much as you can."

Harnessing the placebo effect can be surprisingly powerful, too.

"A lot of [the drinking] experience is about expectations.

"If you go out socially and you drink, you love the idea of drinking.

"A lot of it is about the ritual of it.

"So have the wine glass, but fill it with sparkling water or fill it with these incredible sodas or non-alcoholic wine.

"You might be surprised at how much you feel like you're actually getting the same effect."

Start strength training

Get off the treadmill and get into the weights room to be happier and healthier in 2024.

That's the message that's coming through loud and clear in the science - and it gets more important as we age.

Personal trainer Kyra Seiler has just completed her Masters at AUT in strength and conditioning, and runs a strength training gym coaching busy people through short, intense strength workouts.

Seiler says the benefits of any exercise are well established, but strength training should be in every person's fitness routine.

"The number one thing I want everyone to do is just try and do some sort of resistance training.

"The amount of research that's coming out now in terms of mental health, quality of life; reducing your risk of cancer and type two diabetes… strength training is being shown to be superior to cardiovascular training.

"Start doing it as little as once a week - try 15 minutes."

It's never too late to start, she says.

"Whether you're 50, 60, 70, 80.

"There have been numerous studies showing you can still gain muscle, improve your VO2 max [the volume of oxygen the body uses while exercising; a common marker of fitness] and improve your blood pressure by training as little as 30 minutes once a week."

Eat more fibre

If you've been avoiding grains and toying with low-carb eating, 2024 might be the year to consider adding some grainy bread back into your life, along with lentils, chickpeas, beans and peas.

Fibre is a bit of a stealth super-nutrient - and most of us are not getting enough of it.

As the authors of one recent research paper poetically put it: "In the Western world, our diets are impoverished of fibre".

By not getting a good, regular intake of fibre-containing foods, we're missing out on tons of health benefits.

Local and overseas studies have found higher intakes of dietary fibre or whole grains are associated with a lower risk of early death, as well as lowering the incidence of a wide range of non-communicable diseases and their risk factors.

Eat more fibre and you're more likely to have reduced body weight, lower blood cholesterol and blood pressure, as well as a lower risk of coronary heart disease and type 2 diabetes.

Researchers also speak of what they call "striking reductions" in cancer deaths, cardiovascular disease deaths, stroke, and incidence of colorectal, breast, and oesophageal cancer in those who eat the most fibre.

Gut function and motility, and the diversity of gut bacteria are all improved too.

There's a dose-response relationship here - so the more fibre, the more benefits. Experts say we should aim for at least 25-29 grams of fibre a day.

That might be a stretch for some, since it's estimated we get an average of 20g per day or less.

The type of fibre matters - there's a range of types, and they all do different things - so variety is important.

There's a shortcut to achieving this, that has tons of other upsides: eat lots of plants.

That means as wide a variety as possible of vegetables, fruits, nuts, seeds, grains and legumes: the more, the better.

Add a little of everything into your day for better health by the end of the year.

Change your self-talk

Fiona has a worthy new year's challenge for everyone: stop talking to ourselves negatively.

We are our own worst enemies, she reckons, and "that can be really self-defeating".

"Change the narrative and notice when you're being negative and telling yourself you're not good at things, or you're noticing everything that's gone wrong instead of all the things that have gone right.

"Get rid of the 'shoulds' and then talk to yourself as a best friend.

"What would a best friend say in this situation?

"And if we could just go through the year like that, that would be incredibly protective for all of us."

Develop your optimism muscle

On a related note, Fiona reckons we could all do with a dose of the irrepressible optimism of Pollyanna.

"A habit that changes the lives of people I've seen with a terminal diagnosis of cancer... is to every day, at the end of the day, notice three good things.

"It's not gratitude - because I think for many people that feels really hard.

"It's just going, 'oh, that dinner was delicious'.

"Or, 'I really, really loved the fact the sheets are clean on my bed'."

This helps in a couple of ways, Fiona says, by overriding our inate negativity bias.

"Right now the world is overwhelming.

"We are absolutely inundated with difficult information.

"And our brains will cling onto the negative stuff because evolutionally, that's what kept us safe.

"To counteract that, we have to notice the good things so that our brains can be rewired for optimism."

The science shows the good things don't have to be huge, Fiona emphasises, but this exercise can be a big contributor to resilience.

"If we do it deliberately - and it can be over dinner with kids, or with a partner or with friends or flatmates - noticing the things that went well is protective for all the s**t that's happening right now.

"It's helpful if you are faced with a sudden tragedy.

"We can see what happens in the brain when you do it.

"The people who - even through their darkest times - still go, 'oh, what a delicious salad'; they are able to switch their brains to something small, and then they can switch back to the hard stuff, and it's just easier."

- By Niki Bezzant/ RNZ