We’re talking about circadian rhythm.  From the Latin circa (around) and diem (day), circadian rhythm is any biological process that displays an endogenous, entrainable oscillation of about 24-hours.  These 24-hour rhythms have been widely observed in plants and animals (including we humans).  So, while we all have an inert rhythm – why don’t we “dance” to it?

In the suprachiasmatic nucleus of the brain, we have a “clock,”  which governs when we sleep and rise, taking (in part) its cues from light sources to govern our 24-hour day.  Doctors Michael Roizen and Michael Crupain suggest in their new book, “What to Eat When,” this biological rhythm affects our digestion and hormonal levels,  and it dictates when it’s best to exercise and to eat.  In fact, they propose that “when we eat, is just as important as what we eat.”

Two weight loss studies conducted by Dr. Jakubowicz, of Tel Aviv University, include the effects of circadian rhythm.

In a 12-week study, 93 obese women, were divided into two groups.  The objective for all was to lose weight on a 1400 calorie per day diet consisting of moderate-carb and moderate-fat intake.  The food consumed was the same, except that one group’s breakfast was composed of 700 calories, lunch 500 calories, and dinner 200 calories.  Group 2 did the reverse, 200 calories at breakfast, 500 at lunch and 700 at dinner.

Everyone lost weight.  The big breakfast group lost an average of 17.8 pounds and 3 inches off their waistline. The big dinner group lost 7.3 pounds and 1.4 inches off their waistline.  The more abundant breakfast group also showed significantly lower levels of ghrelin (often referred to as the hunger hormone), and a decrease in insulin, glucose and triglyceride levels.

In another study, 193 obese, non-diabetic adults participated in a 32-week study.  Again, they were divided into two groups.  Men had 1600 calories per day, women 1400 calories.  One group had a low carbohydrate diet with a 300 calorie breakfast; the other was high in both proteins and carbohydrates and always included a dessert for breakfast.  This meal came in at 600 calories.  After the study, the group with the big breakfast lost, on average, 40 pounds more than their peers.  Part of the problem for the low carb, small breakfast group was the participants didn’t endure denial well for 32 weeks.  As mentioned in an earlier post, when faced with deprivation, one can sometimes become depraved.

While the Israeli studies results are compelling, they are supervised diets, and I wouldn’t advise something so drastic without direction from a professional.

In urban America, our days are filled with work, school, and other activities.  We leave homes at different times, not having breakfast as a family unit.  During the day, there is work, school, after-school activities, and appointments.  Our calendars are full.  At the end of the day a family, hopefully, can sit down as a unit for what is usually their largest meal.  Complicating our lives, even more, is the control technology has over us.

So I asked myself, “how can I incorporate a better “when” into my diet day?”  I figured this would be a relatively easy process.  I  was wrong.  Even following the book’s four guidelines can be problematic.  I get up early and have a substantial breakfast (which includes fat, protein and whole grains) by 8 am.  I plan lunch between 12 and 1 pm.  Dinner is my smallest meal, and I try to eat it between 5 and 6 pm.  This is fairly compatible with the guidelines.  However, keeping a consistent mealtime schedule is not as easy as I’d thought.  It’s here the adage, “make plans and life happens,” comes in to play.

The doctors also discuss what to eat when you’re experiencing stress or grief, how to handle health issues and other everyday life challenges that arise.  Importantly, they do speak to “mindful” eating.  Enjoying a meal without phone or text interruption, and eliminating television programming while dining is recommended.

There is science to aligning our circadian clock with our hunger clock.  Do you want to figure out how you can incorporate the “when” into your day?  Read “What to Eat When.”  Some suggestions may be easier to integrate into your life than others, but there is no doubt, better positioning the two rhythms can be beneficial to your well-being.