Boosting your metabolism as you age

Most of us will be familiar with the notion that as we age, we can’t eat the same way as our younger selves once did. For years, the assumption was that this is because your metabolism is slowing as you get older.

But a study of more than 6,400 people, aged 8 days to 95 years, from 29 countries worldwide, shows that metabolism for both men and women really doesn't significantly drop off until you reach the age of 60.

Metabolic rates do change during your early life, but plateau between the ages of 20 and 60, and only decrease by around 1% per year after that. The research also shows that there’s also no effect on metabolic rate from menopause or pregnancy, and very little difference between men and women.

It’s much more likely that weight gain in later life is caused by lifestyle changes, such as being less active, age-related muscle loss (sarcopenia), or overeating.

What is metabolism?

In simple terms, metabolism refers to all of the chemical reactions that occur in your body to keep you alive and functioning. These processes include breathing, heartbeat, and breaking down nutrients from food.

Ultimately, the faster your metabolism, the more calories you burn, the easier it is to lose weight, and the more energetic you’re likely to feel.

The speed of your metabolism is influenced by four main factors:

• Resting metabolic rate (RMR) - the number of calories you burn while resting. Your RMR is essentially the minimum number of calories needed to keep your body alive and functioning.

• Thermic effect of food (TEF) - how many calories you burn through digesting and absorbing food. TEF usually accounts for 10% of daily calories burned.

• Exercise - the number of calories you burn through exercise.

• Non-exercise activity thermogenesis (NEAT) - how many calories you burn doing non-exercise activities, such as moving around, gardening or household chores.

While some factors affecting metabolism - like height - are out of your control, many others - such as activity level - usually aren’t.

Strength training

We all lose muscle mass as we age, as a result of sarcopenia, which usually begins around the age of 50. After this, it’s estimated that a person’s muscle mass decreases by around 1-2% each year, and muscle strength at a rate of 1.5-5% each year. In fact, by the age of 80, people have roughly 30% less muscle than when they were 20.

Strength training offers the usual benefits of exercise, including improved cardiovascular health, but brings an added bonus of building and preserving muscle mass. Over time, this can boost metabolism by increasing the number of calories you burn throughout the day.

Increase daily activity

Your daily activity levels have a big impact on the speed of your metabolism, so incorporating more exercise into your daily routine can make a significant difference to how many calories you burn every day.

Cardio exercise - such as brisk walking, running or cycling - together with non-exercise activity thermogenesis (NEAT), make up roughly 10-30% of daily calories burned. For very active people, this number can stretch as high as 50%

Eat more protein

The speed of your metabolism typically increases for a few hours after eating because of the thermic effect of food (TEF) - the extra calories your body needs to digest, absorb, and process the nutrients in your meal.

Protein causes the largest rise in TEF - and increases your metabolic rate by 15-30%, compared with 5-10% for carbohydrates and 0-3% for fats. For example, consuming 25-30% of your calories from protein can help you burn an extra 80-100 calories per day. Eating protein can also help to keep you feeling fuller for longer and is essential in fighting sarcopenia because of the important role protein plays in preserving and repairing muscle.

Get more sleep

Sleep is intrinsically involved in various hormonal and metabolic processes, and a lack of sleep can slow down your metabolism dramatically. Poor sleep can also lead to muscle loss, which in turn slows down your resting metabolic rate (RMR).

Getting a good night’s sleep can also help prevent overeating. A lack of sleep not only impacts energy levels but also increases levels of the hunger hormone ghrelin while decreasing the fullness hormone leptin. The later you stay awake at night, the more likely you are to start snacking.

Drink more cold water

Drinking cold water can speed up your metabolism by around 10-30% for up to an hour because the body has to use extra energy to heat the water up to body temperature. As well as hydrating the body after a night’s sleep, drinking a big glass of cold water is a great way to kick start your metabolic rate when your first wake up.

Another added benefit of drinking more water is that it helps to fill you up, and various studies have shown that drinking a glass of water half an hour before you eat can help prevent overeating.

Stand, don’t sit

Non-exercise activity thermogenesis (NEAT) is the number of calories we burn through activities other than exercise - for example, standing and completing household chores - and research shows that older adults burn roughly 30% fewer calories through NEAT due to reduced activity levels.

So aside from incorporating more exercise into your daily routine, you could also make a conscious effort to spend more of your day on your feet. Not only is sitting down for long periods bad for our health, but it also burns fewer calories and research suggests that an afternoon of standing up at work can burn an extra 174 calories compared to sitting down.

Start the day with a black coffee

The caffeine in coffee can boost metabolism by 3-11% and promote fat burning which may also contribute to successful weight loss and maintenance. Up to 400mg of caffeine (around four cups) a day appears to be a safe amount for most healthy adults.

To avoid disrupted sleep, it’s recommended not to drink coffee less than six hours before bedtime.