Breakfast like a king, lunch like a prince, dinner like a pauper. You’ve probably heard of this advice by nutritionist and author Adelle Davis, but is it even possible to follow this old adage in our busy lives? Weight loss studies have shown it is easier to lose weight, even up to twice the amount, when you follow the king-prince-pauper pattern. Could this be how to lose weight without exercise?

Chronobiology (the study of circadian and body rhythms) is starting to explain the truth in this saying. It is a fascinating area of research, which continues to reveal the complex nature of our bodies, and how they run best to a 24-hour clock. Not only do we have a central ‘clock’ in our brain, but nearly every organ of our body has its own internal clock—our heart, lungs, kidney and even digestive tracts.

Studies are suggesting that our health and weight may depend on keeping these clocks in sync. Think of the havoc caused to us when we experience jet lag. It is also well known that those who regularly work night shifts are more likely to experience higher rates of obesity, diabetes and heart disease.

Bright light exposure in the morning (ideally between 8am to 11am) is what helps our central clock stay in sync. Interestingly, it is the timing of our meals that can help keep our internal clocks remain in sync.

All of us (not just diabetics) become more insulin resistant as the day goes on, and this improves again by the morning. Insulin resistance means that our body’s ability to keep blood sugars under control worsens and this happens for all of us later in the day. For example:

• The same meal eaten at 8:00pm can cause twice the blood sugar response as the same meal eaten at 8:00am (1).
• In the morning, our muscles are more sensitive to insulin and work more quickly and efficiently to take blood sugar out of the bloodstream and build up energy stores in the muscles.
• These energy stores are made up early on so they can be drawn on through the day.

Our digestive tract works according to a 24-hour clock. Certain gut functions happen more regularly during the day and slow down at night. We use up more energy (calories) from our meals when eaten at breakfast, than if that same meal was eaten later in the day. For example, gut contractions, which help push food through our digestive tract, are more frequent earlier in the day and cease towards night. Our digestive enzyme secretion and stomach emptying cycle work according to our internal clocks too. 

Calorie intake to lose weight

Those struggling with their weight or wondering how many calories per day to lose weight, should consider reducing the amounts they eat later in the day. Many studies are showing this trend. One in particular (2) has observed the following:

• Researchers chose two random groups of people to eat the same meal at either 8am or 8pm.
• Each group switched over to the other time after a week, so both groups had the chance to eat the same meal at either 8am or 8pm.
• They measured the number of calories burned over the three hours after the meal.
• The morning eaters burned an extra 100 calories from the meal compared to the evening eaters.

What was the difference? Food eaten in the morning provides us with much-needed energy, but some of the energy from that morning meal also goes into breaking down, re-assembling and restocking the muscles with a source of energy for the day ahead.

How to keep your ‘clocks’ in sync

1. Always eat breakfast and get plenty of sunlight in the mornings. These are two of the best ways to keep our central and internal clocks functioning at their best.
2. Breakfast like a ‘king’ can be hard, so plan for a substantial lunch instead. Foods to help lose weight include:

• Vegetable and bean soup with a wholegrain roll (made up on the weekend)
• A pre-prepped salad with some drained beans and sweet potato
• Leftover vegetable and tofu curry with rice

3. If possible, eat dinner a littler earlier in the evening. Don’t overdo the quantities either. Try to make sure all food is well and truly finished up by 7pm. Avoid all food for a good 2.5 hours before going to bed.
4. Brush your teeth closer to finishing dinner, as this can help prevent TV snacking.
5. If you have a treat, add it to the end of your dinner and make it small. Our bodies find it hard to process the sugars as the day wears on.
6. Don’t be hard on yourself. The type of food that you eat is more important towards achieving your health goals than the timing. Do the best that you can with your circumstances.  

Tips for shift workers:

• You can’t change your job or the light exposure you get on night shift, but you can try to minimise your food intake overnight.
• Have healthy, appealing foods ready to go once you get home, to avoid reaching for unhealthier options. It is hard to make healthy decisions when you are tired. Set up some soaked chia/oats with fruit, nuts and seeds the day or night before. Eat it once you get home.

While the king-prince-pauper diet may not be the latest weight loss fad, being aware of your calorie intake and chronobiology ‘clocks’ is proven to be a sustainable solution to maintaining a healthy weight. If you’re looking for more information on weight loss and maintenance, explore Food As Medicine — an award-winning Australian cookbook and health book equipping you to make smarter choices for your best health.

This article was written by Australian nutritionist and dietitian Marcia Townend.

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References:

1. Van Cauter E, Polonsky KS, Scheen AJ. Roles of circadian rhythmicity and sleep in human glucose regulation. Endocr Rev. 1997;18(5):716-38.
2. Bo S, Fadda M, Castiglione A, et al. Is the timing of caloric intake associated with variation in diet-induced thermogenesis and in the metabolic pattern? A randomised cross-over study. Int J Obes (Lond). 2015;39(12):1689-95.
3. Jakubowicz D, Barnea M, Wainstein J, Froy O. High caloric intake at breakfast vs. dinner differentially influences weight loss of overweight and obese women. Obesity (Silver Spring). 2013;21(12):2504-12.