By Dr Adam Simon

Does how often you eat and when you eat affect weight loss?

Does how often you eat and when you eat affect how much weight you gain or lose? We examine the cold, hard facts on this controversial issue.

Eating little and often is frequently put forward as an easy way to aid weight loss, while eating at night is popularly thought to be a big no-no for those looking to get trim.

But are these just old wives' tales, or does the timing of when and how often you eat have an impact on your ability to shed the pounds?

In this guide, we'll take a look at the evidence behind these claims and get to the bottom of this much-debated issue.

Little and Often

The theory behind eating small meals frequently seems pretty sound at a glance. Supporters of this idea claim the body must have to work harder to process calories taken throughout the day, rather in two or three big lumps.

Grazing is also thought to prevent you from overeating at meal times, by keeping you full throughout the day.

But what does the science say?

Back in 2011, the International Society of Sports Nutrition reviewed all the available evidence, from observational studies to controlled experiments and even research involving animals.

It came to the conclusion that increasing meal frequency didn't appear to have any affect on the body composition of people who don't get much exercise.

However, the review did note that eating little and often did seem to have positive effects in terms of 'markers of health' like cholesterol levels and insulin production.

Similarly, it also claimed that eating more frequently did appear to help in making people feel fuller and control their appetites.

Another 2011 study published in the journal of Nutrition and Dietetics had similar findings. After reviewing a range of research from various papers and journals, it concluded that:

Overall current evidence does not suggest that manipulating eating frequency greatly benefits weight and health.

Putting the final nail in the coffin of eating little and often - a meta-analysis (a study of studies) that looked into the issue once again in 2015 found that while changes to meal frequency could, in some circumstances, offer some benefits the available evidence suggested that changes in this area had few practical benefits.

However, it did warn of emerging evidence that having an irregular eating pattern could have a negative effect on metabolism. So it seems that it's more important to have a set frequency and stick with it if you're trying to lose weight.

Eating Late at Night

If you eat late at night, then go to sleep for about eight hours or so, your body must have a harder time burning off those calories? While it may sound like an appealing theory, is it backed up by evidence?

In 2007, a study put 12 obese women on a calorie-controlled diet over three, 18-day periods. At first, these were spread evenly five times a day, then limited to between nine to 11am and finally between six to eight in the evening. Across all three periods, no significant difference was found in levels of weight and body fat.

Research from 2008, admitted 160 healthy people to a clinical research ward and let them eat whenever they wanted from a computerised vending machine that recorded when and what they ate. Those who favoured eating between 11pm and 5am were branded 'night eaters' and this behaviour was found to predict weight gain.

However, the study's authors conceded that the relationship between eating at night and weight gain was unclear.

It remains to be determined whether this behaviour indicates abnormal sleep patterns leading to night time wakefulness and food intake in those prone to weight gain, they said.

trial on nearly 80 obese police offers showed that eating the majority of their daily carbohydrate (carbs) at dinner time lost more weight than those on a day-eating schedule.

These results echoed findings from a 1997 study, which found participants who ate most of their food in the evening saw greater weight loss than those who dined in the morning (although the difference wasn't significant).

But the results of both these studies were contradicted by two trials from 2013, which both showed daytime eating to be better than night time dining.

Unlike meal frequency, it seems the jury is still out on whether eating at night can hinder weight loss. While studies do suggest daytime dining has a slight edge, eating of an evening isn't likely to be a make-or-break factor when it comes to losing weight.

But, if you know being tired makes you more likely to reach for the comfort food it's probably best to try and fill up during the day.

And You?

Do your dieting experiences reflect the evidence or are you still unconvinced? Whatever your views, we always love to hear from you, so leave us a comment below or get in touch via Twitter and Facebook.