There are several diet and meal plans stating what we should or should not eat if we want to lose weight. Low carbohydrate diets such as Carnivore and Ketogenic advise to cut bread, pasta and fruit. While high carbohydrate diets like vegan and vegetarian advise to cut meat. Some meal plans improve health and help with weight loss more than others (looking at you Mediterranean diet!), but there is still a lot of confusion around when we eat our meals, and whether or not that timing is important. With intermittent fasting becoming so popular, we must explore whether the time of day we eat our meals is also a contributing factor to our weight loss success.
Breakfast
Breakfast, and whether you eat one or not, is hereditary. There has been a strong link between genetics and breakfast eaters, as we have started to understand the different chronotypes of people. While there is some debate on how many different chronotypes exist, the two main categories are: Morning types and Evening types. Morning types are early risers who have an easier time eating breakfast, and also tend to be a healthier weight. Evening types tend to sleep in and prefer having their first meal later in the day and generally have a large meal in the evenings. Studies causally link skipping breakfast with obesity, though more longitudinal research is needed to identify solely whether or not the skipping of breakfast is the key driver of obesity.
Lunch
Genetics play a lesser role for lunch but can still affect the timing of our meal by 38%. This is seen in the twins study, which is still less than the 56% with breakfast. There was a notable difference between early lunch eaters and late lunch eaters, those eating before or after 3pm. Eating a late lunch, after 3pm, can hinder weight loss. Furthermore, eating most calories before 3pm is correlated with healthier weights and a more diverse microbiota, aka a healthier gut.
Dinner
Dinner time has nothing to do with genetics and everything to do with habits and/or your chronotype. Individuals with evening chronotype who eat a late dinner, within 2 hours of bedtime, see an increase in probability of obesity 5-fold. Some of this has to do with limited activity at bedtime, but some also has to do with our body’s secretion of melatonin. When melatonin levels are high, such as in the hours before bedtime, glucose tolerance goes down. When glucose tolerance decreases, more fat is stored, and weight gain is noted.
Time Restricted Eating
Time restricted eating has shown to improve insulin sensitivity, increasing blood glucose control, can help improve blood pressure management and cardiovascular health by decreasing inflammation and can promote weight loss. Intermittent fasting (IF) is a form of time restricted eating that has gained a lot of attention due to its positive correlation with weight loss and overall health status. A 12-hour fasting period- i.e. eating from 8am – 8pm- is enough of a fast to see improvements in health status and to facilitate weight loss. There is still more research needing to be done to explore the benefits of lengthier fasts.
Our Registered Dietitian, Karissa Lucio’s Tips:
Whether you are a morning or evening chronotype, these tips will help you get on track with your meal timing.
- Eat your first meal of the day within 2 hours of waking up. If you wake up nauseous or with an uneasy stomach, drink 8-12oz room temperature water before anything else. You might also try limiting caffeinated beverages like coffee, tea or energy drinks or at the very least waiting until you have breakfast to consume them- caffeine will curb your appetite and might make your stomach issues worse.
- Eat every 4-6 hours throughout the day. Eating more regularly during the day will help you make better dietary decisions and will also help you better manage portion sizes. This will also ensure you do not fall into the trap of eating a late lunch and an even later dinner, which can promote weight gain.
- Stop eating 3 hours before bedtime. While challenging, this is the most important step to improving your health status and digestion (see you later heart burn!)
It is important to have a plan in place to help make these changes easier. Try sticking to the same general mealtimes to make it into a habit. This will also help you become more familiar with your personal hunger and fullness cues, making portion control second nature over time.
Looking to further your knowledge on nutrition? Join our next Nutrition Education Class with Karissa Lucio on May 29, 2025, from 1:30 – 2:30pm at Collinfield. At every class, Karissa shares a new nutritious recipe, cooking it live to inspire healthy eating habits. RSVP is required, and attendees under 18 must be accompanied by an adult. RSVP here.
For more tailored, one-on-one guidance, that caters to your specific lifestyle and personal goals, call 877-800-5722 to schedule an appointment with Registered Dietitian, Karissa Lucio.
Blog post written by Karissa Lucio RD, LD, CDCES, Lone Star Circle of Care Registered Dietitian.
References:
Lopez-Minguez J, Gómez-Abellán P, Garaulet M. Timing of Breakfast, Lunch, and Dinner. Effects on Obesity and Metabolic Risk. Nutrients. 2019 Nov 1;11(11):2624. doi: 10.3390/nu11112624. PMID: 31684003; PMCID: PMC6893547.
Vasim I, Majeed CN, DeBoer MD. Intermittent Fasting and Metabolic Health. Nutrients. 2022 Jan 31;14(3):631. doi: 10.3390/nu14030631. PMID: 35276989; PMCID: PMC8839325.
