Wednesday, June 4, 2014

Lean vs. Overweight: Post-Breakfast-Skipping Binge is Overweight-Specific. Lean Subjects Reduce Both Energy (-26%) & Sugar Intake (14%), When They Skip Breakfast

It always hits the (already) big ones.
A recent study that was conducted by a group of researchers from the Roehampton University, and the Universities of Northampton and Hull in London took an interesting and totally overdue approach to dispel the myths that revolve around the anti-obesity effects of breakfast. In the said study, a team of researchers recruited 37 participants who were assigned to one out of four groups on the basis of their body mass index (BMI) - normal weight BMI <25 kg/m² | or overweight/obese BMI > 25 kg/m² | habitual breakfast eaters | habitual breakfast omitters.

Subsequently, even the latter, i.e. the breakfast eaters were requested  to  eat  breakfast  for  an  entire  week. The BREAKFAST week was followed by a one week wash-out and an entire  week during which the subjects had to omit breakfast.
Learn more about fasting and eating / skipping breakfast at the SuppVersity

Breakfast and Circadian Rhythm

Does Meal Timing Matter?

Breakfast & Glucose Metab.

Breaking the Fast, Cardio & the Brain

Does the Break- Fast-Myth Break?

Breakfast? (Un?) Biased Review
Over the course of the whole study period, all subjects hat do keep detailed 7-day food diaries, reporting what was consumed and the timing of consumption were completed for each breakfast condition.
Figure 1: Lean (left) and overweight (right) subjects react very different to breakfast skipping (Reeves. 2014)
As the data in Figure 1 already reveals, the total energy intake was significantly higher during the breakfast than the no breakfast week. But just as the scientists say, the present study did also reveal a "significant effects of timing on energy intakes": More energy was consumed during the afternoon in the no breakfast week compared to the breakfast week.

Timing and body weight, both make a difference!

In general, overweight participants consumed greater amounts of  energy than normal weight  participants (surprise ;-) in the early evening - the effect was even more pronounced for those of them who were regular breakfast omitters and thus used to feasting in the afternoon / evening.

Overall, this sounds as if having breakfast regularly was a very good idea, but unlike some people want to make you believe, the total energy intake does count. The same is yet also true for the amount of sugar, which skyrocketed in the overweight subjects in the no breakfast week. Running around on empty and being unable to tap into their affluent energy depots on the hips and around the waist, the insulin resistant (don't tell me about "healthy obesity!") overweight part of the study participants gravitated towards readily available energy intake.
Table 1: Mean sugar and micronutrient intakes in breakfast and no-breakfast conditions (Reeves. 2014)
Bottom line: Paired with the reduced folate and iron intake in the non-breakfast week, the previously outlined results of the study at hand highlight once more the practical value of having breakfast for the average American who is neither willing nor able to track his energy and macronutrient intake on a daily basis. In a controlled diet scenario,  on the other hand, lean individuals have no reason to eat breakfast, if they feel that intermittent fasting (=breakfast skeeping) helps them to stick to their planned energy intake.

If you take another look at the data in Table 1 to the right, you will after all realize that the lean study participants were able to live of their fat stores and did not have to resort to Snickers, Twinkies and *bs* "protein bars" with a sugar content of 85% - the sugar intake of the habitual breakfast eaters decreased significantly by 31% while their fibre intake remained stable in conjunction with the 26% reduction in energy intake this alone should have been enough to she a couple of pounds of body fat... So what? Good bye "healthy" breakfast cereals ;-)
References:
  • Reeves, Sue, et al. "Experimental manipulation of breakfast in normal and overweight/obese participants is associated with changes to nutrient and energy intake consumption patterns." Physiology & Behavior | Available online 24 May 2014.