When You Eat Is Why You're Fat

Do you sometimes wait to eat meals? It’s not helping your waistline.

At this point, it’s practically conventional wisdom: If you skip breakfast, you’re going to have trouble losing weight, probably because you overeat later in the day (the Mayo Clinic offers a handful of other reasons why). A new study in the International Journal of Obesity takes the notion of timing and weight loss even further, claiming that when you eat meals throughout the day affects how easily you drop pounds.

The study, performed by researchers from Brigham and Women’s Hospital, the University of Murcia, and Tufts University, split 420 overweight participants into groups of early and late eaters. All of the participants followed a weight-loss diet, but half had lunch before 3 p.m., and half had lunch afterwards. It’s culturally important that the study focused on lunch; all the participants lived in Spain, where it’s the main meal of the day (and where 40% of the day’s calories are eaten).

Even though diet, energy intake, estimated energy expenditure, appetite hormone levels, and sleep duration were basically the same for all participants, the people who ate late lunches lost less weight—and lost it at a slower rate, too. The participants dropped weight at the same pace for the first five weeks of the 20-week study, but after that, those eating later saw their weight loss sputter to a halt. By the end of the study, they had lost 22% less weight than the earlier eaters.

The study summary points out that the later eaters often skipped breakfast and had higher insulin resistance, but not enough to explain the dramatic results.

And so, the authors conclude, "Eating late may influence the success of weight-loss therapy. Novel therapeutic strategies should incorporate not only the caloric intake and macronutrient distribution—as is classically done—but also the timing of food." In many parts of the world where dinner is the main meal of the day, eating earlier isn’t so easy. But for anyone serious about weight loss, it’s worth considering how timing might affect you.

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  • Zoran Knezevic

    Am I just acid or this article is written like lawyers letter where you need a specialist consultation to actually understand it.

  • mirahsan2

    Meanwhile at work, the constant onslaught of rude customers and the boss breathing down my neck didn't let me eat since breakfast at 7am, it is now 7pm and I'm stuck in traffic and won't be able to eat till 8pm where my wife will yell at me about something and the kids will be out of the way not wanting to see Daddy. Oh look, Jay Leno is on...

  • Melissa

    All bunk. Eat when you're hungry--and only enough to maintain your lean body mass. Wait for true hunger (felt in throat), not fake hunger (felt in stomach,or as light-headedness, or as the myth 'low blood sugar'). Eat high-nutrient foods packed with color, phytochemicals, antioxidants, nuts, beans, veggies, fruits--high quality calories and not empty ones.

  • mischevious interloper

    harsh crowd. too bad people don't know how to vet original research. IF ITS IN A JOURNAL ITS INFERENCES MUST ALL BE TRUE!!!

    can you believe people think it's natural for a healthy human to faint from missing a meal? or even 3? we have an entire separate energy system--lipid metabolism--that works brilliantly to keep us supplied with energy--IF you're not metabolically deranged. if you are, here's how to fix it:

    basically, for those at all uncertain, melissa is right.

  • Eric Wyler

    "low blood sugar" is not a myth. People die from hypoglycemia every year.

    That said, the last sentence is valuable.

  • Juls

    Great, Melissa...this is indeed the best advice based on a lot of other articles and studies I read. 
    Unfortunatelly media shares fast consuming information without checking other sources and broader studies. Our bodies are wise enough to tell us when to eat....when hungry!

  • Dwayne

    Sure, don't listen to scientific research, follow the advice of someone crying "bunk" in the comments.

  • ByondPolitics

    Bad advice could cause fainting & that leads to traumatic brain injuries.

  • Teknographica

    I lost 20 pounds by simply switching my normal morning and evening meals. so much for anecdotes.

  • Dave Gerczak

    This study is wrong based on many other studies and real world results.  Google Martin Berkhan and LeanGains.  Personally, I lost 72 pounds using intermittent fasting, proper diet, exercise, skipping breakfast daily and dropped from 24% bodyfat to 6.5%, 234 to 162 at my leanest.  - Dave Gerczak

  • kayumochi

    Great to see some successful IF practitioners here like myself. I average one meal a day, am almost 50 years old and have a lean muscular body that most 20-something men can only dream about.

  • Nikos

    *Applause*  Great response Dave. Another HORRID study pushed to the masses. I've also been a solid practitioner of IF based on all of Martins articles and his website. And yet somehow ridiculous studies like this still come out, and people continue to digest them without thought. Now let me go eat all of my 300g intake of carbs between 8pm and sleep time  for another day so I can stay in single digit body fat percentage. 

  • Juls

     I always wondered if intermittent fasting actually works...great to know it did.. congrats for your weight loss!

  • Max

    I agree with you. I'm an IF practitioner too. I lost 8 lbs after I plateaued in 14% bodyfat using IF. now I'm 9-10% with cheat meals. >:D