1. Count calories
Put simply, a calorie is a measure of the amount of energy in food. To maintain a healthy weight, the average man needs approximately 2,500 calories while the average woman needs around 2,000, according to NHS guidelines. And to lose weight, we need to burn more calories than we consume.
The caveats? Calorie-counting can be confusing – and misleading. Foods labelled as 'low-fat' or 'low-calorie' may be nutritionally deplete, whereas foods that are relatively high in calories, such as olive oil or nuts, boast vital heart-boosting properties.
A recent report, published in the journal Open Heart, suggests we should stop counting calories and focus instead on the nutritional value of food.
Related: Should we stop counting calories?
2. Step on the scales
If you're trying to slim down, weighing yourself regularly can help you track your progress. It will also help you calculate your body mass index (BMI) to find out if you're a healthy weight for your height (http://www.nhs.uk/Tools/Pages/Healthyweightcalculator.aspx).
The caveats? Your weight may fluctuate due to factors such as water retention, hormone levels and what you've just eaten – so it's a good idea to weigh yourself at the same time once a week, using the same scales and wearing the same clothes.
It's also important to remember that muscle weighs more than fat, so if you're embarking on an exercise regime, your weight may actually increase even though you'll be in better shape.
Related: Is a weekly weigh-in enough?
3. Measure your waist
Carrying excess fat around your middle puts you at increased risk of type 2 diabetes and heart disease – which is why many doctors believe measuring your waist is a better indicator of health than BMI.
Keep your waist measurement to less than half your height and you could significantly boost your life expectancy, say researchers at City University London.
The caveats? It can be tricky to measure yourself accurately. A couple of pointers? Your waist is precisely halfway between your hip bone and bottom rib, usually where your belly button is. It can help to use a mirror so you can see what you're doing.
Related: How to keep your hourglass figure
4. Get your five-a-day
Eat at least five portions of fruit and vegetables daily and you'll be well on your way to getting all the nutrients you need for optimum health. And the more you eat, the better: people who eat seven or more daily portions have a 42 per cent lower risk of death at any time than those who eat less than one, says a University College London study.
The caveats? Choose your fruit and veg wisely: some smoothies, tinned fruit, ready meals and juices, for example, contain large amounts of sugar and/or salt.
Potatoes don't count at all – and beans and pulses only count as one portion, no matter how much you eat.
Related: Eat the rainbow – the colourful foods that will help your health
5. Keep track of alcohol units
Regularly drinking more than the recommended daily alcohol limits can significantly raise your risk of serious health problems, including various cancers and heart disease.
Current guidelines state that men shouldn't regularly exceed three to four units per day while women should have no more than two to three units. To find out how many units are in your favourite tipple, use the Drinkaware calculator (https://www.drinkaware.co.uk/understand-your-drinking/unit-calculator)
The caveats? Because alcohol content varies so much from drink to drink, it can be hard to keep track of the exact units you consume. And advice is changing all the time. As more research emerges linking alcohol to cancer, the NHS is set to slash daily limits further.
Related: Are you drinking more than you think?
6. Monitor your blood pressure
High blood pressure can put you at increased risk of heart disease and stroke, but it rarely has any symptoms. The only way of knowing if there's a problem is to get it checked.
You should get tested at least once every five years – but if you're at increased risk, you'll need to be checked every year. You can get tested at your GP's surgery or a pharmacy – or use a home-testing kit.
The caveats? It pays to be prepared. To avoid a temporary hike in your blood pressure which will give an inaccurate picture of your health, arrive in plenty of time for your appointment and make sure you empty your bladder.
It may also pay to get tested by a nurse, rather than a doctor: doctors routinely record higher levels because patients feel more stressed at being assessed by someone in a white coat, say researchers at the University of Exeter.
Related: What you need to know about blood pressure
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