It might not surprise you that in today’s on-the-go, snacking has become a way of life. In the early 1970s meals made up more than 80% of adult calorie intake and snacks only contributed less than 20%. Fast forward to today, snacks now contribute 23% (1). Evidence showed that healthy, non-shift-working adults eat an average of 4.2-10.5 times daily (2). The only time most people do not eat is from 1 AM to 6 AM.
The times of day and night that we eat affect our body’s circadian rhythm, which regulates our metabolism. Meal timing can have serious implications for the development of obesity, cardiovascular diseases, and type 2 diabetes (1).
Let’s review how important meal timing is and how it can affect metabolism. We’ll also take a look at the different health effects of specific eating patterns and see what experts found. The tips listed below should help you get easy-to-follow eating menus and find one that will work best for your lifestyle, preferences, and goals.
Meal Timing Is As Important As What You Eat
Although the body is not an actual watch, it does have an internal clock that runs nearly 24/7. This is termed as “circadian rhythm.” It helps your body function on a schedule and adjust to sleep, environmental changes, and behaviors such as eating.
While it is clear that the type of food you eat can affect your body, the timing may also have an effect on the following:
- Metabolism
- Body-weight regulation
- Management of obesity-related disease and other metabolic disorders
- Sleep cycle
How Does Food Timing and Sleeping Pattern Affect Metabolism?
Food Timing
The connection between obesity and the body’s natural biorhythms goes beyond the type of food that you eat. Restricting what you eat to a certain time daily sets your body on a schedule. Evidence suggests that trying to delay this window can take several days before your body adapts (3). This explains why splitting up 3 meals into 6 can be an adjustment for someone going on a diet.
Regular mealtimes likewise play a long-term role in body weight. You are expected to feel hungry every 3 to 5 hours, but your body is also used to your regular schedule. It is best to eat at the same time daily. Healthy, filling snacks such as cheese and vegetables can be very helpful in curbing your appetite.
In some cases of meal timing, switching when you eat bigger meals can make a huge difference. One study found that eating more for breakfast than dinner can help you lose weight and get better metabolism (4).
Sleeping Pattern
Lack of sleep can also disrupt your body’s internal clock, metabolism, and hormonal balance. Evidence showed that this disruption can confuse the body’s signal for hunger and tiredness, thus increasing your cravings for starchy and sugary foods (5).
Another evidence found that mice who were exposed to light at night gained 50% more weight than those who enjoyed dark nights (6). Also, people who eat and sleep out of their circadian rhythm may develop metabolic syndrome, which is a combination of disorders that increases your risk of heart disease, stroke, and diabetes (7).
When Is The Best Time to Eat?
Trying to determine the best time to eat can be very confusing, and experts are looking at different factors. One study showed that eating late lunch, usually after 3 PM, can help you lose more weight than eating early (8). There is also no difference in weight loss for the timing of breakfast and dinner meals. Another study pointed out that eating only from 6 AM to 7 PM can help reduce your overall calorie intake by as much as 244 (9). By having less time eating, you consume fewer calories. A longer overnight fast can likewise increase fat loss because the body goes into ketosis, which requires the use of fat for energy.
Is It Helpful to Skip Breakfast?
Studies show mixed results as to whether breakfast intake contributes to weight loss. One study found that eating breakfast can help reduce dietary fat intake and impulsive snacking (10). Another evidence, however, said that eating more calories early in the morning will not necessarily make you eat less during the entire day (11).
The American Heart Association (AHA) thinks that fewer adults eat breakfast today and it coincides with the increase in obesity rate (1). One study also showed that nearly 75% of breakfast skippers did not meet two-thirds of the RDA for vitamins and minerals compared to those who are eating breakfast (12). Skipping breakfast regularly may increase your blood sugar and cholesterol levels and put you at risk of developing high blood pressure and type 2 diabetes.
While there is an association between skipping breakfast and obesity, the effect on weight loss is limited, probably because people tend to eat several times throughout the day. Total daily calorie intake and food choices have a greater impact on weight than skipping breakfast alone.
You can still lose weight healthily by fitting a balanced breakfast into your daily routine. It is very important to consume more of the nutrients essential to good health. Here are some tips:
- Eat breakfast with your family. It can be a fun time together if your evenings are busy with work overtime, after school activities, and other events
- If you need to leave early, pack a healthy, balanced meal for your morning trip to work or school. Whole grain toast with nut butter and a piece of fruit make a simple, delicious, and nutritious breakfast!
- You may also save time by making breakfast the night before. How about blending fat-free milk, plain Greek yogurt, unflavored almond or soy milk, and cups of fresh fruits and vegetables? A healthy smoothie can make for a perfect breakfast too!
Defining Lunch, Dinner, And Snacks And The Best Time to Eat Them
The AHA concludes that using the time of day to define lunch and dinner is not appropriate because of several cultural differences (1). Several people work full time on a graveyard shift, rotating schedules, and other employer arranged irregular schedules. This greatly impacts meal timing. For people who sleep during the day and eat their meal at midnight, do they have “lunch?”
The AHA says meals contain at least 210 calories. Any eating occasion with less amount of calories can be called a snack. Eating more meals and fewer snacks is associated with healthier food choices that include more fruits, vegetables, whole grains, and lean protein sources, which are all essential to weight loss.
Always choose nutrient-dense foods instead of processed products that are rich in sugar, fat, salt, and calories. Instead of munching on an energy bar, why not eat a fruit with nut butter? Whole grains or plain popcorn can be a perfect substitute for a bag of chips. If you want something sweet, satisfy your cravings with a home-made trail mix that combines dried fruits, nuts, and seeds.
Planning meals around veggies should also be quick and easy! Stir-fry veggies, chicken or fish, and brown rice make a satisfying meal that can be eaten anytime!
As for timing, eating late at night, which is2 hours before going to bed, is not recommended. It seems to increase CVD risk. People who work and eat at night often have higher blood sugar, cholesterol, and triglyceride levels. Disruption of circadian rhythms contributes to the increased risk of cardiovascular diseases.
You may have probably heard of the recommendation, “Eat like a king at breakfast, like a queen at lunch, and like a pauper at dinner.” This may actually have scientific merit. Evidence showed that eating the largest meal of the day late at night can increase cardio-metabolic risk factors. Timing meals and snacks to fit within 10-12 hours like between 6 AM to 6 PM can help promote weight loss and decrease cardiovascular risk (1).
Will Meal Frequency Affect Weight Loss?
Is eating three full meals better than snacking or eating small meals several times daily? Experts say there isn’t enough evidence to prove that changing the number of times you eat has a huge impact on weight or CVD risk factors. The key isn’t the number of times you eat, but rather the type of food you eat as well as the time. Consuming an overall healthy variety of foods that include whole grains, lean protein sources, fruits, and vegetables and avoiding highly processed foods with high sodium, fat, and calorie contents are a well-known way to improve health and promote weight loss, no matter how many times you eat.
Is Intermittent Fasting Good for Weight Loss?
There has been an increased interest in IF both to lose weight as well as to improve overall health. There are several types of IF, but the most common are alternate-day fasting and periodic fasting.
Alternate-day fasting involves an “eating day,” consuming not more than 25% of your baseline calorie needs within 24 hours, alternated with a “feast day,” when you can eat as much as you want. Periodic fasting, on the other hand, involves one or two non-consecutive days of fasting, with unlimited food options the rest of the week.
Studies on both types of fasting show that people can lose 3-8% of their body weight after 3-24 weeks. The impact on health parameters, however, is variable. Others show a decrease in total cholesterol and LDL cholesterol, while some did not experience any effect. Triglyceride levels may decrease along with weight loss. The more you lose weight, the lower your triglyceride levels become. Blood pressure is expected to lower if you lose 6-7% of your body weight, and insulin resistance may decrease when you lose at least 4% of your body weight (1).
Many are also practicing 16-hour fasting with an 8-hour eating window. A decrease in fat mass is achievable, especially when done with resistance training (13). Intermittent fasting can:
- Have the same effects as intensive exercise
- Reduce the resting heart rate
- Decrease blood pressure
- Curb appetite
- Aid in weight loss
- Prevent coronary artery disease
Evidence also found that IF works as an alternative to calorie restriction for weight loss in patients with type 2 DM (14). IF is also believed to have more benefits than permanent calorie restriction (15).
But remember, no one strategy is perfect for everyone. You have to check if intermittent fasting is suitable for your needs and lifestyle. If you choose to try IF to lose weight, you have to make sure that on non-fasting days, you will eat whole foods and avoid those that are high in sugar, salt, and calories.
Key Takeaway
Calorie restriction is certainly the most effective method of weight loss, but the timing of your meals may affect how your weight loss journey goes. The recommended route to perfectly manage your food intake is to have an eating schedule that fits your lifestyle.
Generally, it is best to limit meals and snacks to a 10-12 hour timeframe during the day and avoid eating later in the evening. You have to get a variety of nutrient-packed foods instead of processed and packaged products. Eat a larger proportion of calories earlier in the day than dinner and evening snacks.
IF is good, if you don’t have any other medical conditions. Otherwise, it is best to ask for approval and guidance from a doctor or dietician.
References:
(1) https://www.ncbi.nlm.nih.gov/pubmed/28137935
(2) https://www.ncbi.nlm.nih.gov/pubmed/26411343
(3) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4078443/
(4) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4078443/
(5) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2831987/
(6) https://www.pnas.org/content/107/43/18664.abstract
(7) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2831987/
(8) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3756673/
(9) https://www.frontiersin.org/articles/10.3389/fpubh.2014.00059/full
(10) https://academic.oup.com/ajcn/article-abstract/55/3/645/4715167
(11) https://nutritionj.biomedcentral.com/articles/10.1186/1475-2891-10-5
(12) https://www.ncbi.nlm.nih.gov/pubmed/9850113
(13) https://jissn.biomedcentral.com/articles/10.1186/1550-2783-11-S1-P25
(14) https://www.ncbi.nlm.nih.gov/pubmed/24993615
(15) https://www.ncbi.nlm.nih.gov/pubmed/26653760
