Meal Timing: Does When You Eat Impact Your Ability to Lose Weight?

Meal Timing: Does When You Eat Impact Your Ability to Lose Weight?

Meal Timing: Does When You Eat Impact Your Ability to Lose Weight?Most people focus on what they eat and how much they eat when they’re trying to lose weight or avoid gaining weight – but what about WHEN you eat? Does that have an impact? A recent study showed that meal timing can affect how slowly or quickly you lose weight or whether you lose it at all. If you’re a person who likes to eat meals late in the day, it may work against you when you’re trying to shed excess weight. Here’s the full story.

Meal Timing and Weight Loss: Does When You Eat Matter?

Researchers from the Brigham and Women’s Hospital and University of Murcia in Spain monitored the weight loss and dining habits of 420 overweight and obese Spaniards for 20 weeks. The participants had similar calorie intakes and sleep habits. The only difference was one group ate lunch earlier in the day, before 3:00 P.M, while the other group ate lunch late in the day, after 3:00 P.M.

Lunch is the big meal of the day in Spain and the meal at which Spaniards consume the most calories. Even though the participants in this study took in a roughly equivalent number of calories, the ones that ate earlier in the day lost more weight and lost it more quickly than those that lunched late in the day. Despite the differences in weight loss, the participants had comparable levels of appetite hormones like leptin and ghrelin and expended a similar number of calories. How can you explain these results?

There were some interesting observations. The late day eaters that had more trouble losing weight were more likely to skip breakfast or eat less at breakfast than early diners. Some research suggests that people who eat breakfast have an easier time controlling their weight. Eating breakfast, especially one high in protein, helps to reduce cravings later in the day that can lead to unhealthy food choices and mindless snacking. Plus, starting the day with a protein-rich breakfast has a metabolism-boosting effect, giving your metabolism the “jump start” it needs after an overnight fast.

Why Might Eating Late Make It Harder to Control Your Weight?

Some experts believe circadian rhythms are a factor in weight control. You have an internal clock that’s regulated by environmental cues like light and dark. When you eat or sleep at times that aren’t in sync with your internal clock, it triggers changes in hormones that impact everything from your appetite to your metabolism, making it easier to gain weight.

What about Late-Night Eating?

Eating dinner late and snacking after hours is just as bad for your waistline as eating lunch late. Some studies show eating dinner and snacking after 8:00 P.M. is linked with weight gain. People who work night shifts and sleep during the day may also be at greater risk for putting on pounds. Research in animals shows when mice eat at times they would normally be sleeping, they tend to eat more and become obese.

One study showed men who worked alternating day and night shifts were more prone towards weight gain. Of course, there are a number of factors at work here. People who work these types of schedules have more problems sleeping, and inadequate sleep has been linked with weight gain, possibly by elevating cortisol levels. People who work at night also tend to make less healthy food choices and expend less energy overall. Even more disturbingly, they’re at greater risk for health problems like type 2 diabetes.

Another study showed that nurses who switched from working day shifts to night shifts gained weight over a two year period. If you have a choice, choose the day shift!

 What Does This Mean?

There’s growing evidence that circadian rhythms play a role in weight, overall health and even your mood. How can you get “in sync” with your internal clock? Go to bed as early as possible after the sun goes down, start the day with a healthy breakfast that’s high in protein, eat an early lunch and dinner and avoid snacking after dinner. These are lifestyle habits that work in your favor when you’re trying to lose weight or avoid gaining it.

When you eat may not be as important as what you eat or how much you put on your plate but it does have an impact on how easy it is to control your weight based on preliminary research in animals and humans. Make sure you’re eating right – and at the right times.



Int J Obes (Lond). 2013 Apr;37(4):604-11.

WebMD. “Lose Weight, Eat Breakfast”

Obesity (Silver Spring). 2008 Aug;16(8):1887-93.

PLOS Medicine. “Rotating Night Shift Work and Risk of Type 2 Diabetes: Two Prospective Cohort Studies in Women”

J Occup Environ Med. 2011 Feb;53(2):153-8.


3 thoughts on “Meal Timing: Does When You Eat Impact Your Ability to Lose Weight?

  1. Unfortunately not everyone is able to do this because of job/family life.
    Because of my husband’s work we do not eat dinner until 830-10pm most nights. He has ate like this for most of his life and is not overweight. I recently married him and am hoping it will not affect me. I have always eaten dinner a littler earlier and then had a snack before bed, now it is just reversed.

  2. Even though this article is all over the place, I agree with the fact that late eating is extremely bad for more reasons than weight gain only, but it is definitely proven by habits of other cultures. Unlike Americans, Europeans typically eat their biggest meal in the middle of the day. Their ‘dinner’ consists of a snack or light meal (not cooked) in the early evening between 5 and 7pm. As a result, Europeans are less likely to be overweight. If you’ve ever traveled there (Germany, Italy, France in particular), it hits you right away, how many skinny people see and how long it takes before you actually see a fat person.
    Aside from this, I think it is extremely uncomfortable to lie down after a heavy meal, let alone sleep. The body has no use for all of this food and calories at the end of the day. It has other jobs to do during sleep and I would expect that digestion during sleep is not efficient. It makes perfect sense that it will then store it as fat. From personal experience I can say that stopping the big dinner habit is the easiest way to control your weight.

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