Will eating after 7 p.m. cause weight gain? Understanding the facts behind the myth

Myth: 

You must stop eating by a 7 pm for weight loss/maintenance.

Truth:

As your day winds down, your body begins to slow down in the evening, and you go into recovery mode. That includes digestion. Your body’s systems work more efficiently in the daytime while you are the most active, including increased saliva production and how quickly the food you eat is metabolized and digested. In contrast, at night, our system slows down and food takes longer to pass through our GI tract. This may affect how our bodies are able to regulate our blood sugar, which could lead to insulin resistance. Insulin resistance can then in turn increase our risk of developing diabetes and cardiovascular disease, of which we already are at an increased risk as we age. Plus, eating later into the night offers fewer opportunities for exercise, and the lack of movement following a meal increases our risk for weight gain, diabetes, and cardiovascular disease.

There was a small research study (only 20 individuals) that looked at the difference between eating an identical dinner at 6 pm versus 10 pm, then went to bed at 11 pm. The earlier diners had lower glucose levels following their meals compared to the later diners. This means that the individuals who ate at 10 pm had higher glucose levels for a longer period of time. The later diners also had less breakdown of their meal, so they were not metabolizing their food as efficiently. Another study (11 individuals) looked at the differences between adding a mid-morning snack versus a late-night snack. Those that had a later snack had a greater increase in total and LDL (bad) cholesterol after 2 weeks. The snacks were identical and consisted of fat and carbohydrates.

And finally, when looking at how well our bodies digest food, later-night eating causes our systems to burn less calories in the process of digestion. We are up to 50% better at burning calories during daytime meals than in the evening just through the process of eating and breaking down our foods. These studies do support the myth that eating later into the night may cause weight gain and health risks. However, looking at the sample size and length of the studies, the evidence is not that strong.

What does this mean?

For most of us, eating our larger meals during the daytime hours is ideal. This allows us more time to digest but also burn calories by exercising or doing daily activities like cleaning, laundry, or running errands. We do not need to eat a heavy meal right before bed, as this may also lead to poor sleep quality. And while the studies referenced give an argument as to WHY you should not eat after a certain point, there are factors that have not been considered. It is also important to evaluate WHAT you are eating. Are you having a big bowl of ice cream after 3 solid meals per day? Are you eating a hefty portion of chips and salsa, maybe washing it down with a soft drink? This is what is referred to as “empty calories.” These foods do not provide any nutritional benefit and are full of simple carbohydrates and/or sodium. This is by far not the same as if you were busy throughout the early evening and did not get a chance to eat your dinner until 7:30 pm. In this case, your body is depending on those calories to help you reach your nutritional needs for the day. Going to bed hungry can also lead to a poor night’s sleep by waking up often.

There is also no magic cut-off time for eating, and everyone’s lifestyle will determine what makes the most sense for them. If you are a night owl that stays up late and sleeps in, having your last meal at 6 pm may also leave you hungry. Your body is on a different time clock than others that may go to bed early and get up with the sun. There may be others that may have worked the graveyard shift and are used to being more active in the evening. For those, having a heavier meal later in the day may make more sense. That being said, if you suffer from acid reflux, allowing some time to digest before laying down with help reduce your symptoms.

It is also important to evaluate WHY you are eating. Maybe you did not get enough calories or macronutrients in during the day. Or you are bored, nervous, or tired and feel the need for some comfort foods/snacks. These situations are different and should therefore be handled differently. If you are snacking because you are hungry, to help regulate blood sugar, or your medication requires you to eat something with it, then it is a good idea to eat. Also, honor your hunger cues. If your stomach is growling, you need to eat. But be mindful of what you are eating. A lighter snack of some vegetables/dip, an apple and peanut butter, or cheese and crackers will be enough instead of a big plate of pasta or a burger and fries. 

However, if you are someone who struggles with excessive snacking at night out of boredom, stress, or any other reason, your body is not relying on those calories or nutrients as a need, but more of a want. Adding a nutritious snack could be a way to combat the excessive calories, focusing more on lower calorie, lower sugar, and lower sodium foods. Bonus points if you are adding a protein or fiber source, as this will help regulate blood sugar and keep you full and satisfied longer. Other options are evaluating your evening meal, or your day as a whole. If you are not consuming enough calories during the day, you will naturally be hungry later. Another option would be to look at a hobby that may help keep your hands busy while winding down at night. This could be working on a puzzle, knitting, playing cards, etc.

The takeaway

Our bodies are better at digesting and metabolizing our food earlier in the day while we are most active. An occasional meal later than your usual mealtime will not cause weight gain. The bigger culprit would be consistent snacking of unneeded calories. It is important to evaluate your meals prior to the evening to make sure you are meeting your needs, so you do not have to rely on late night calories. If you are feeling like your needs were not met and you will sleep better with additional food, opt for a healthy balanced snack that is low in added sugar and sodium but also contains protein and fiber.

ArchWell Health members have the opportunity to discuss nutrition concerns or questions at every appointment. Your primary care provider can help you better understand how carbs fit into your overall nutrition plan.

The article provides information designed to complement your personal health management. It does not provide medical advice and not meant to replace professional medical advice. Linking to other websites does not imply any endorsement of the material on such websites.

References:

Apd, F. H. (2021, July 6). When should you stop eating at night? Healthline. https://www.healthline.com/nutrition/what-time-should-you-stop-eating#effects-of-eating-late

Gilpin, R. (2024, June 19). Is it a bad thing to go to sleep hungry? - Sleep advisor. Sleep Advisor. https://www.sleepadvisor.org/going-to-bed-hungry/

Idz. (2024). Saturated facts: The Real Science Behind Diet Myths. Penguin Life.