If you've been counting calories to no avail, new reserach may have the answer to shedding the kilos.
The latest theory on effective weight loss involves a practice called 'chrononutrition', which involves controlling eating patterns, and it's said to have a profound effect on our waistlines.
Nutritionist and clinical dietitian Mr Filip Koidis, founder of W1Nutritionist, told the Daily Mail: "Successful weight management is not all about discipline and saying 'no' to all the foods that tempt you, as this kind of behaviour very often results in negative outcomes and episodes of binge eating.
"Achieving satiety internally, is all about getting your appetite hormones to function optimally - these are affected by sleep, routine and also exercise."
The theory goes that the "how" and "when" of diets is just as important as what we actually eat, and the new research looks at factors such as our body clock and regularity of meals, as part of understanding the weight loss process.
Here are five factors to look at if you're trying to lose weight:
Get enough sleep
Research has shown that we should all aim for seven hours of shut-eye each night.
Many studies have pointed to the fact that after a poor sleep, we are more likely to consume excess calories.
A lack of shut-eye also promotes the production of cortisol, which can wreck havoc on the metabolism and regulation of the imune system.
"Early sleepers have a 25 per cent better response in diets, both psychological and physiological reasons," Koidis said.
"Try to manipulate the carbohydrate, fat and protein content to help create optimum sleep. A large carbohydrate load will create some insulin resistance which in turn may affect melatonin and cortisol - and therefore sleep."
Foods such as raspberries, almonds, walnuts and kiwifruit are all natural sources of the sleep hormone melatonin, while meat, dairy and carbohydrates help to supress it.
Eat light meals at night
"Diet induced thermogenesis, known as DIT, which is energy your body uses to process the food you consume, is 50 per cent lower during the evening meal," Koidis told the Daily Mail.
So if you're only nibbling all day and consuming most of your calories at night, you're burning up significantly less energy on a daily basis.
One study compared two groups eating 1400 calories per day, and found the group that ate most calories for breakfast had far greater weight loss than those who consumed more calories at night.
Stick to a routine
Believe it or not, maintaining a schedule rather than eating at erratic times helps to shed weight - even if the food you are eating remains exactly the same.
Research in this area is still limited, but one theory is that when your body is used to a schedule, your metabolism and hormones can digest food more efficiently at meal times.
Watch out for alcohol
While it's a good idea not to drink on an empty stomach, Koidis says it can have a negative affect on weight loss.
"Alcohol interferes with your metabolism as your body stops processing any existing food and starts working towards excreting alcohol," Koidis explained.
"So combining alcohol with food or eating after having drunk substantially is not preferable when trying to manage your weight. For a healthy individual, planning your meals and eating two and a half hours before going out for a drink, and then avoiding food until the morning after would be ideal."
Opt for high protein, low carb foods if you are drinking alcohol, such as eggs, nuts and low fat meats.
Since feeling full is as much controlled by the mind as it is by the stomach, we need to give ourselves time to eat properly.
Studies have shown that 21 minutes is the optimal amount of time for satiety signals to reach the brain after eating, so meals should be no shorter than this.
"Mindful eating is essential for weight management, and several studies have shown that eating mindfully results in greater satiety, improved food experience and better hormonal response," Koidis told the Daily Mail.
As well as putting down your phone and not eating in front of the TV, Koidis says another trick to mindful munching is listening to yourself chew.
"Listening to yourself chewing helps focus the mind on what's going on on your plate."