Belaboring a point isn't always a bad thing. Before your first solo skydive, for instance, don't you want your instructor repeating exactly where the reserve cord is and how to use it ad nauseam?

While I hope my use of repetition never makes you ill, I will at times harp on, hash over, and hammer home because it's easy for you in the midst of all the many other things you absolutely need to do to lose sight of the elements essential to optimal health.And one of those is how your food choices affect more than obvious factors like weight loss, weight gain, energy level, and mood.According to Dr. Henry Emmons, a psychiatrist who's written two books on the topic, The Chemistry of Joy and The Chemistry of Calm, these other factors seem to be a secret. He claims most people are "oblivious" to the ways in which food consumption affects their lives.In the past few weeks, I've tried to battle that oblivion. One article explained that some experts now fear the rise in autism is linked to the considerable use of sugar and chemicals found in the typical American diet; another, that the theory of epigenetics suggests your present food choices impact the health of your children and even grandchildren; a third, that even though you may be genetically disposed to develop certain diseases like cancer, healthy eating habits can suppress the expression of those genes.And here's a related element worthy of repeating ad nauseam: when you eat affects your health.For years, for example, eating breakfast daily has been said to be a key in long-term weight loss. In fact, eating breakfast daily is done religiously by 78 percent of the members of the National Weight Control Registry, an organization where membership requires a 30-pound-or-more weight loss and successful maintenance of the loss for at least one year.Research first presented at Neuroscience 2012 explains the weight-loss benefit to breakfast. In this study, researchers took functional magnetic resonance images (MRIs) of the brains of 21 normal-weight subjects on different mornings. Each time, all subjects were instructed not to have breakfast beforehand.During some visits, the MRIs were taken 90 minutes after a 750-calorie breakfast was consumed. Other times, the MRIs were taken before the big breakfast.On all occasions, lunch was served and researchers tracked how much the subjects ate. The tracking confirmed what you'd expect: when breakfast was delayed, subjects ate more at lunch.The subjects were shown pictures of high-calorie and low-calorie foods during the MRIs. When breakfast was delayed, something besides hunger and cals consumed at lunch increased. So did the level of activity in the part of the brain that influences judgments about foods' pleasantness and value.As a result, the appeal of high-calorie foods increased in the subjects who had delayed breakfast.This result reinforces a belief first established in various other studies: skipping breakfast actually increases the difficulty of long-term weight loss because the practice causes dieters to seek out high-cal foods by the end of the day.Related research performed at the University of Missouri-Columbia added important details about the optimal breakfast. It should contain a fair amount of protein, at least 35 grams, so you feel fuller longer than if you consume a high-carb breakfast.And later in the day, you'll then experience fewer food cravings.Another study focused on the effect of when calories are consumed was published last summer in the journal Obesity.In it, Tel Aviv University researchers had 93 obese women adhere to a 1,400-calorie-a-day diet consisting of a moderate amount of fats and carbohydrates. All ate the same meals, but at different times of the day.Half of the subjects consumed half their daily calories at dinner. After 12 weeks, these women lost an average of 7.3 pounds and 1.4 inches from their waists.The other half consumed half their daily calories at breakfast. In 12 weeks, they lost an average of 17.8 pounds and 3 inches from their waists.Additionally, the big-breakfast group recorded decreases in insulin, blood glucose, and lower triglyceride levels, which lessen the likelihood of eventually developing diabetes or heart disease.Another reason to strive to keep blood glucose levels low is because even increases that don't cause diabetes could cause dementia.University of Washington researchers reviewed data on more than 2,000 dementia-free patients in Seattle's Group Health Cooperative. At the conclusion of the study seven years later, 524 from the group, whose average starting age at was 76, developed dementia.After eliminating diabetics who developed dementia, the researchers still found a 20 percent increased risk for developing the disease for those with slightly higher blood sugar levels. For subjects who had diabetes, slightly higher blood sugar levels than other diabetics increased the risk of dementia 40 percent.