As we get older, our bodies change – and so do the kinds of foods we need to eat to lose weight and stay healthy. From the age of 30 onwards, our metabolism begins to gradually decline, which means we need fewer calories than we did in our younger years.
To maintain body weight, a woman in her fifties needs around 200 calories less per day than in her thirties. In addition, older women need to eat more protein in order to maintain the same muscle mass as a younger woman.
See also: How the menopause affects your weight
See also: Best low-calorie foods to fill you up
With fewer calories to spare, it's even more important to avoid empty calories in things like crisps and biscuits. If you're a fifty-something woman, it can be a good idea to cut back on sugar, as well as the amount of carbohydrate on your plate, replacing it with vegetables (particularly leafy greens) and protein.
And while everyone's nutrient needs change after the age of 50, there are certain disease-fighting compounds and nutrients that are of particularly relevant for women who want to protect against memory loss, hip fractures, and breast and stomach cancers.
Low in calories, berries are a great choice if you're watching your weight – try them with low-fat yoghurt to replace fattening deserts. Fiftysomething women have another good reason to add berries to their diet.
According to a report in the Annals of Neurology, older women who eat strawberries and blueberries at least twice a week can delay memory decline by up to two and a half years. Phytochemicals in the berries are thought to increase blood flow to the brain and reduce harmful inflammation, helping to slow age-related memory decline.
Meanwhile, a separate 2007 Harvard study found that older women who ate two servings of strawberries a week had less inflammation in their blood vessels, lowering their risk of cardiovascular disease.
2. Leafy greens
You might know that calcium is vital for bone strength, but a major study from the US shows that women need another key bone builder, vitamin K, to help prevent hip fracture in their later years.
Researchers analysed the diets of more than 72,000 women aged 38-74 for a decade. Those who ate higher amounts of vitamin K (110 micrograms or more) were 30 percent less likely to break a hip than women who ate very little of the vitamin. Not only that, but a separate study suggests that vitamin K could play an important role in protecting the skin's elasticity and help to prevent wrinkles.
Eating dark, leafy greens such as kale and spinach could also help look after your little grey cells as you age. People who ate one to two servings of leafy greens per day had the same cognitive ability as those 11 years younger who rarely ate them, according to research presented at the American Society for Nutrition annual meeting.
You don't have to be vegetarian to enjoy the health benefits of beans. Studies show that eating beans or lentils each day can help to lower LDL or "bad" cholesterol by five percent. A separate study of people with type 2 diabetes found that eating a cup of beans or lentils each day, along with a healthy diet, lowered hemoglobin A1c, a marker of blood sugar control.
High in protein and fibre, beans will fill you up for longer and help fight food cravings – making it easier to avoid temptation foods. Try adding a tin of chickpeas, lentils or kidney beans to casseroles, soups, salads and curries.
4. Nuts (especially walnuts)
If you don't already eat nuts as part of your diet, now is a good time to start. Eating an ounce of mixed nuts each day as part of Mediterranean-style diet can reduce the risk of heart attack, stroke, and death from heart disease by as much as 28 percent, according to Spanish researchers.
Another study published in the American Journal of Clinical Nutrition found that eating walnuts, which are a good source of plant-based omega-3 fats called alpha-linolenic acids, are particularly good for lowering your risk of cardiovascular disease.
5. Green tea
The benefits of green tea are well documented. Researchers at Vanderbilt-Ingram Cancer Center studied the diets of 75,000 middle-aged women and found that those who regularly sipped green tea were less likely to develop digestive cancers, including bowel, stomach and oesophageal cancer.
Women who drank the most green tea had the greatest protection – those who sipped the drink three times a week for more than six months had a 17 percent lower risk of developing a digestive cancer. That increased to 21 percent for those who drank two to three cups a day.
The risk for heart disease increases dramatically in women over 55, so including more cholesterol-lowering foods into your diet is a good idea. Oats are rich in a type of soluble fiber called beta glucan which is great for reducing 'bad' cholesterol.
Because they release their energy slowly, oats are low on the GI scale and a good choice for weight watchers. Porridge with berries and a little natural yoghurt for breakfast is a good choice – helping you to stay trim as well as healthy.