TruBlog

By Mike Parnes

What follows is a collection of some of the most common nutrition myths I am faced with on a regular basis while working as a san diego personal trainer. I will discuss seven of my favorite myths over three blogs. Many of these make it into our conventional wisdom due to over-simplification of scientific studies or simply misunderstanding the findings and passing these misunderstandings on as truth. Other myths persist due to lots of marketing dollars coming out of very well funded companies that depend on consumers believing their products are x, y, and z. This list is by no means exhaustive and I intentionally left out any myths regarding carbohydrates because a more lengthy discussion of them can be found in a prior blog I wrote here.

Myth #1 – If I eat late I will gain weight (or won’t lose)
Several of the most well-entrenched myths involve the timing of eating and weight gain or healthy weight loss. Despite popular diet-book recommendations for limiting nocturnal eating, the studies on meal ingestion patterns, and the associated weight or fat gain or loss, do not suggest that reducing late eating is an effective weight control mechanism. The objective of these studies on animals and humans is to determine whether altered meal timing patterns affect weight and body composition changes during a weight loss intervention. One well-designed, but small sample study reported in the Journal of Nutrition (1) found that weight loss was greater with consumption of large morning meals and fat-free mass is preserved more with large evening meals. If fitness professionals based their recommendation on this one peer review’s study, they would have to say “If you want to lose weight, eat early, but to preserve your lean tissue, eat late.” Hence the dilemma that faces every fitness professional in translating complicated (and often conflicting research) for the consumer. In the case of late day eating, there is no agreement in the literature to suggest that later meal ingestion, provided calories remain constant, prevents weight loss or causes weight gain. What’s most important to note is weight gain and weight loss occur over a continuum (a period of time of weeks, months, years), and not hour by hour.
Behaviorally, when it comes to late night eating, many people consume more calories because it has been too long since they have last eaten and they are very hungry. This doesn’t mean eating before bed makes you gain weight. It confirms that eating too much makes you gain weight – an important difference.

Myth #2 — Exercising on an empty stomach improves fat burning
Several popular books promote this unfortunate misunderstanding of human physiology. Like cars, the human body performs very well when fed properly. There are many “metabolic mills” operating in the body at all times, to produce energy from the macronutrients ingested. Picture a well-running factory with many interdependent production stations. When food slows down or comes to a halt, so does production.
Technically, while the body may burn more fat exercising on an empty stomach, it also burns more muscle, which no fitness participant wants. Ultimately, without available glucose, the body can’t jump start all of the mills and the result is a sub-optimal effort that burns less, rather than more, fat and calories.

1. Halberg F. Some aspects of the chronobiology of nutrition: more work is needed on “when to eat.” J Nutr 1989;119:333-343.

Tags: Healthy Weight Loss, Metabolic Nutrition, San Diego Personal Trainer

This entry was posted on Wednesday, March 3rd, 2010 at 10:59 am and is filed under Healthy Weight Loss, Metabolic Nutrition, Nutrition, Optimal Health, Uncategorized, Weight Loss. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.