When we think of early dinner, our minds go straight to a geriatric early-bird special. While New Yorkers and most of Europe are probably scoffing at the idea of dinner by 6 at the latest, wellness, weight maintenance, and energy levels have been saying otherwise. Though we don’t need to hold ourselves to a rigid early-dinner-only mentality, it’s a smart call at certain times of the month (speaking for the ladies). We tend to need more cals and carbs closer to our periods, so don’t feel bad if a later dinner or some evening snacks are a necessity—we don’t want to sacrifice healthy blood sugar for strict ideals.
However, early dinner times can support intermittent fasting, weight-loss goals, and digestion for a multitude of reasons. We spoke with registered dietitian, MS, and LDN Rachel Swanson, founder of the nutrition consulting practice Diet Doctors, LLC to relay just what those multitudes are.
Her work focuses on developing personalized treatment plans for cardiometabolic health, longevity practices, weight loss, disease prevention, and optimal maternal-fetal outcomes, so she understands that it’s not always just about what we eat, and often about when.
“An ‘early dinner’ is highly subjective,” Swanson points out. “This can be considered 5 p.m. for some, whereas others may consider 8 p.m. early. So having some construct around this conversation will be helpful.” In this case, nutritionally, we are defining “early dinner” as one that allows for a two- to three-hour fasting window to take place before bed.
“This recommendation is part of a bigger, and much more sophisticated, biological picture. The benefit of an early dinner has to do with the fact that as the day winds down, the body needs less food for energy and should be entering a fasting state. Capping your intake more than two hours before bed allows for an extended overnight fasting window to take place—the essential downtime your body needs to facilitate detoxification and cellular repair,” Swanson explains.
But that’s just the obvious part. “Timing food intake around our innate circadian rhythm (our sleep-wake cycles) in this way influences a tremendous amount of physiological processes downstream—including that of metabolic function and even fat loss. That’s because the timing of food intake affects how our metabolism processes calories. Evidence in humans suggests that eating out of sync with our circadian rhythm (like eating a late dinner during the biological night, so to speak) can promote weight gain and metabolic dysfunction. On the other hand, eating in sync with our biological clock has been shown to improve parameters of metabolic health, such as the reduction of fasting blood sugar and improvement in insulin sensitivity.
The circadian system orchestrates metabolism in a 24-hour cycle, giving rise to rhythms in energy expenditure, appetite, insulin sensitivity, and other metabolic processes. Many of these processes, including insulin sensitivity and the thermic effect of food (TEF), peak in the morning or around noontime.” Many people find this cycle to be at odds with what Western society has deemed the norm. We’re used to light breakfasts, skipping lunch, and glorifying a heavy, complex meal at dinner time. Science suggests we flip-flop that, and consume more cals earlier in the day for better energy assimilation, proper digestion, and sustained daily energy.
“Our circadian system orchestrates metabolism in a 24-hour cycle: we have innate rhythms in our energy expenditure, appetite, insulin sensitivity, and glucose disposal (blood sugar utilization). Insulin sensitivity and the thermic effect of food (the increase in metabolic rate after ingestion of a meal), for example, peak in the morning or around noontime, and plummet late at night.
This is one of the main reasons to avoid eating large meals late at night. It’s fascinating to think that we can stack the deck for favorable metabolic conditions simply by when we eat, completely independent from what we eat.”