We all have eating patterns dictated by our everyday life, occupation, and biological preferences. Most of us view the timing of these patterns as something peripheral without knowing how fundamental they can be for our health, performance, mood, and overall quality of life.
Most people focus on the macronutrient, micronutrient, and calorie content of their food without paying the necessary attention to the scheduling of their meals. Indeed, the macros, micros, and calories you consume play a major role in determining optimal nutrition. Timing, however, can be equally important as it is a core factor regulating mood, hunger, and energy levels.
In this blog, we dive into the impact that meal timing has on the various aspects of our life and the choice we can make to turn the scheduling of our meals into an ally to our health and wellness.
What determines optimal meal timing?
Three main components determine one’s nutrition: calories, macronutrients, and micronutrients. The three main calories or energy sources are macronutrients: fats, carbohydrates, and protein. Micronutrients are substances like vitamins and minerals that do not contain calories but provide essential nutrients that are critical to our health and performance. Consequently, optimal meal timing is the optimal timing of our calories, macronutrient, and micronutrient intake during the day.
What are the benefits of optimizing my meals?
Correctly timing your meals and snacks can benefit overall health and athletic performance. These include:
- Weight Loss
- Appetite Control
- Blood Sugar Regulation
- Energy For Cardio And Endurance Exercise
- Increased Muscle Strength, Size, And Recovery
Let’s look at these benefits and see what the research recommends.
What The Research Says On Meal Timing
Fortunately for us, there isn’t a shortage of evidence regarding research on meal timing. Hundred of clinical trials have been performed on thousands of subjects that have examined how meal timing can affect health, performance, and other variables in sedentary, obese, and athletic populations.
After reading this section, you’ll practically have your Ph.D. in meal timing.
Regarding weight loss, almost every study on meal timing has shown that eating more at the beginning of the day and gradually reducing portion sizes towards the evening can have positive effects.
A landmark study conducted in 1997 required subjects to complete two six-week diet periods that delivered similar calories (~ 1950 kcals) and similar macronutrient composition. In one group, the participants consumed 70% of their total daily calories during breakfast, while in the other study group, participants consumed 70% of their total daily calories during dinner. The researchers discovered more significant weight loss in the group that ate most of their daily calories at breakfast.
More recently, a study by Jakubowicz et al. had overweight and obese women consume 1400 calories daily for 12 weeks. One group ate 50% of their daily calories (700 kcals) during breakfast, 35% during lunch (500 kcals), and 15% during dinner (200 kcals), while the other group ate the exact opposite distribution, 15% for breakfast (200 kcals), 35% for lunch (500 kcals) and 50% for dinner (700 kcals). Approximately 2.5 times more weight was lost, and significantly more significant changes in waist circumference and body mass index values were observed when most calories were consumed at breakfast. Also, triglyceride levels decreased by 34%, more significant improvements in glucose and insulin were observed, and feelings of satiety were improved in the group that consumed most of their calories at breakfast.
The key point from these two studies indicates that if weight loss is your goal, eat more in the morning and less in the evening.
Just as eating more in the morning and less in the evening helps with weight loss, the same can be said about appetite control and suppression.
A 2019 study published in the Obesity journal demonstrates this. For this study, researchers compared two groups of people (early eating and the control group) who ate the same three meals per day for four days but at different times. The early eating group ate the majority of their calories during the morning. The control group consumed the majority of their calories in the evening.
On the fourth day of the study, both groups had their metabolism measured, a process that includes the analysis of the calories, fats, and carbohydrates burned. Both groups also rated various measures of appetite like hunger, desire to eat, and fullness. The researcher also measured levels of hunger hormones in each group. The results were fascinating. The early eating group had a higher calorie and fat burn rate while also having lower ghrelin levels, a hormone that’s responsible for inciting hunger. The group also reported less hunger need and desire to eat than the control group.
If appetite control is ever an issue, eating most of your calories at breakfast and lunch can have significantly favorable effects.
Blood Sugar Regulation
Having your blood sugar out of control can pose serious problems for your health and well-being. Blood sugar spikes can cause you to feel anxious and jittery and may lead to deadly conditions such as diabetes over time. On the contrary, blood sugar dips can cause hypoglycemia, a state that leads to feelings of lightheadedness and fatigue.
The timing of macronutrients is the key determinant for regulating blood sugar spikes. Specifically, several studies have shown that consuming most of your carbohydrates earlier in the day can lead to fewer blood sugar spikes and, ultimately, a more stable blood glucose profile. This can help mitigate feelings of fatigue and low energy caused by hypoglycemia (i.e., the state during which blood sugar levels are lower than they should) and moments of agitation and anxiety caused by blood sugar spikes.
For instance, studies have shown that the exact amount of carbohydrates may have a massively different effect on your blood sugar levels depending on the time you consume them. In other words, eating a bowl of pasta at 10 pm may yield up to twice the blood glucose spike compared to eating the same meal at 10 am.
Overall, scheduling your carbohydrate intake earlier in the day can play a big part in helping to avoid the lows and highs of blood sugar levels, help keep blood glucose levels steady and thus keep energized and mentally focused.
Muscle & Strenght Development and Recovery
Muscle and strength development relies heavily on two hormones: testosterone and growth hormone (GF). Optimizing your nutrition so that these two hormones’ secretion reaches the highest possible levels is paramount if you want to maximize your strength and muscle gains.
Specifically, testosterone and GF levels should peak during training and especially during sleep when most muscle restoration and development occur. Both hormones are essential to overall health, muscle development, physical recovery, and attainment of one’s maximum height. Moreover, they are important for physical recovery, which is essential for preventing injuries.
Both hormones are adversely affected by the ingestion of carbohydrates, specifically those with a high glycemic index.
To better understand the impact of carbohydrate ingestion on testosterone and GH concentration, we should first understand the basic principles of carbohydrate metabolism. After ingesting carbohydrates, they are broken down into glucose, a sugar that enters your bloodstream. Glucose can be toxic to your tissue leading, and this causes our bodies to want to remove it from the bloodstream as fast as possible. This is achieved through the secretion of insulin, a hormone that enables glucose molecules to enter cells where they can be burned and thus get removed from the bloodstream. The higher the glycemic index of a carbohydrate, the faster its conversion into glucose in the bloodstream and the more acute the secretion of insulin is in order to remove them.
Both testosterone and GH concentrations are inversely correlated with blood glucose and insulin concentrations. This means that when you consume carbohydrates that cause your blood glucose to spike, your testosterone and GH levels will diminish. Specifically, studies have shown a 3-day period of overeating, that is, consuming more calories than those required to maintain body weight, led to an 80% decline in GH levels in healthy individuals.
To help mitigate these effects, one should optimize carbohydrate intake to avoid blood glucose and insulin spikes during training and sleep, the periods when both testosterone and GH reach their peak to aid in muscle development. The general recommendation for achieving this is to avoid high glycemic index carbohydrates during or immediately before weight lifting sessions and avoid consuming carbohydrates at least 3 hours before going to bed.
Energy For Cardio And Endurance Exercise
Contrary to muscle and strength development training, endurance training typically requires the ingestion of carbohydrates as the energy requirements of the session are substantial. Although carbohydrate consumption during the workout will inevitably lower testosterone and GH levels, choosing low glycemic index carbohydrates will mitigate this phenomenon. Moreover, the slow-burning nature of low glycemic carbohydrates enables one to have a more constant supply of energy and prevent the notorious glucose spike that’s almost always followed by a glucose dip that brings about feelings of fatigue. So overall, if one is engaging in a long (i.e. more than 60 minutes) endurance workout session and feels that fueling during training is essential, then it’s recommended to consume carbohydrates with as low a glycemic index as possible.
It’s important to note, however, that the number of carbohydrates one consumes during training can vary substantially from person to person. Even when consuming low glycemic index carbohydrates, overconsumption can still lead to a spike in blood glucose followed by a dip and the accompanying feeling of fatigue. As a result, it is essential to know how many carbohydrates one expends during training to accurately determine the amount that needs to be consumed and avoid blood glucose spikes.
When and what you eat can affect your health and exercise performance. Therefore, thinking about meal timing as much as you think about the quantity and quality of food is critical to achieving optimal nutrition. The basic principles of meal timing are:
- For weight loss and appetite control, eat most calories in the morning. As the famous saying goes, eat breakfast like a king, lunch like a prince, and dinner like a pauper.
- To keep blood glucose steady, eat every 3-4 hours. This will help you avoid blood sugar spikes while keeping you energized and focused.
- Eat low glycemic index carbs leading up to and during endurance exercise to top off muscle glycogen and elevate blood glucose.
- Avoid eating during resistance training sessions.
- Avoid eating three hours before bed to maximize your testosterone and growth hormone levels during sleep.