5 sources of hidden calories in your food, which could explain why you've put on weight but don't know why

• You don't need to count calories to lose, gain, or maintain your weight.
• However, it can be helpful to know which foods are the most energy-dense.

Whether you count calories or not, the unit of energy plays a role in weight loss, gain, and maintenance.

Knowing how many calories certain items contain can be helpful if you're trying to lose fat, build muscle, maintain your weight, or can't work out why your weight has changed.

Some foods are much more energy-dense than you might think — if, for example, you've started cooking with a little more oil than you used to, or getting frappuccinos instead of americanos, those changes could make a difference to your weight.

However, calories aren't to be feared and there's nothing wrong with enjoying high-calorie foods. It's simply a case of arming yourself with the knowledge to help you consume the right balance.

Graeme Tomlinson, a personal trainer and fat loss coach, shared five examples of "hidden calories" in food and drink that you may not be aware of.

1. Cooking oils

"Cooking oils are often overlooked, but can consistently add significant calories each day," Tomlinson said.

A tablespoon of cooking oil contains around 140 calories, but using a smaller amount, about five milliliters, you can still lubricate your pan for around 45 calories, Tomlinson said.

However, olive oil in particular has lots of health benefits so is worth keeping in your diet, just bear in mind that it's energy-dense.

2. Coffee beverages

"Many don't realize that you can make a simple adjustment to your 'on the go' coffee that can save you hundreds if not thousands of calories each week," Tomlinson said.

If you like milky coffees, switching from whole milk to skim milk will reduce the calories. And if you enjoy coffee drinks with syrups, ask the barista for fewer pumps or a sugar-free syrup.

3. High-fat meat

"The cuts of meat you regularly consume can also have a huge say on your fat loss progress," Tomlinson said.

For example, 200 grams of 20% fat beef mince contains around 504 calories but the same amount at 5% contains 248 calories.

Similarly, opting for chicken breast over thighs or venison instead of beef can reduce the calories in your meal.

4. Spreads and dressings

"Spreads like mayonnaise and salad dressings can also add relatively large amounts of calories to a meal despite appearing insignificant," Tomlinson said.

One tablespoon of mayonnaise contains about 95 calories, for example.

If you're trying to stick to a calorie deficit, Tomlinson recommends switching to lower-calorie versions or cutting down your portions.

5. Nibbles

If you're counting calories, it's very common to underestimate how much you consume each day, which could be another reason why you're putting on weight or struggling to lose it.

"Forgetting about calorie-dense nibbles or finishing off someone else's food may appear insignificant at the time, but over time this can add up," Tomlinson said.

Whether that's your kids' crusts, a handful of chips while cooking, or a spoonful of peanut butter from the jar, it all counts.