Micronutrient focus may reduce cravings
By David Dunaief, M.D.
If we needed any more proof, this past year has been a good reminder that many things influence our eating behavior, including food addictions, boredom, lack of sleep and stress. This can make weight management or weight loss very difficult to achieve.
Unfortunately, awareness of a food’s caloric impact doesn’t always matter, either. Studies assessing the impact of nutrition labeling in restaurants gave us a clear view of this issue: knowing an item’s calories either doesn’t alter behavior or encourages higher calorie purchases (1, 2).
Does this mean we are doomed to acquiesce to temptation? Actually, no: It is not solely about willpower. Changing diet composition is more important.
How can we alter the dynamic? In my clinical experience, increasing the quality of food has a tremendous impact. Foods that are the most micronutrient dense, such as plant-based foods, rather than those that are solely focused on macronutrient density, such as protein, carbohydrates and fats, tend to be the most satisfying. In a week to a few months, one of the first things patients notice is a significant reduction in cravings. But don’t take my word for it. Let’s look at the evidence.
Examining refined carbohydrates
Many of us know that refined carbohydrates are not beneficial. Worse, however, a randomized control trial showed refined carbohydrates may cause food addiction (3). Certain sections of the brain involved in cravings and reward are affected by high-glycemic foods, as shown by MRI scans of trial subjects.
Study participants consumed a 500-calorie shake with either a high-glycemic index or a low-glycemic index. They were blinded (unaware) as to which they were drinking. The ones who drank the high-glycemic shake had higher levels of glucose in their blood initially, followed by a significant decline in glucose levels and increased hunger four hours later. The region of the brain that is related to addiction, the nucleus accumbens, showed a spike in activity with the high-glycemic intake.
According to the authors, this effect may occur regardless of the number of calories consumed. Granted, this was a very small study, but it was well designed. High-glycemic foods include carbohydrates, such as white flour, sugar and white potatoes. The conclusion: Everyone, but especially those trying to lose weight, should avoid refined carbohydrates. Calorie composition matters.
Comparing macronutrients
We tend to focus on macronutrients when looking at diets. These include protein, carbohydrates and fats, but are these the elements that have the greatest impact on weight loss? In an RCT, when comparing different macronutrient combinations, there was very little difference among groups, nor was there much success in helping obese patients reduce their weight (4, 5). Only 15 percent of patients achieved a 10 percent reduction in weight after two years.
The four different macronutrient diet combinations involved overall calorie restriction. In addition, each combination had either high protein, high fat; average protein, high fat; high protein, low fat; or low protein, low fat. Carbohydrates ranged from low to moderate (35 percent) in the first group to high (65 percent) in the last group. This was another well-designed study, involving 811 participants with an average BMI of 33 kg/m², which is classified as obese.
Again, focusing primarily on macronutrient levels and calorie counts did very little to improve results.
Adding micronutrients
In an epidemiological study looking at National Health and Nutrition Examination Survey data, results demonstrate that those who are overweight and obese tend to be lacking in micronutrients (6). These include carotenoids, such as lutein, zeaxanthin, beta-carotene, alpha-carotene and beta-cryptoxanthin, as well as vitamin B12, folate and vitamins C, E and D.
Unfortunately, taking supplements won’t solve the problem; supplements don’t compensate for missing micronutrients. Quite the contrary, micronutrients from supplements are not the same as those from foods. With a few exceptions, such as vitamin D and potentially B12, most micronutrient levels can be raised without supplementation, by adding variety to your diet. Please ask your doctor.
Lowering cortisol levels
The good news is that once people lose weight, they may be able to continue to keep the weight off. In a prospective (forward-looking) study, results show that once obese patients lose weight, the levels of cortisol metabolite excretion decrease significantly (7).
Why is this important? Cortisol is a glucocorticoid, which means it raises the level of glucose and is involved in mediating visceral or belly fat. This type of fat has been thought to coat internal organs, such as the liver, and result in nonalcoholic fatty liver disease. Decreasing the level of cortisol metabolite may also result in a lower propensity toward insulin resistance and may decrease the risk of cardiovascular mortality. This is an encouraging preliminary, yet small, study involving women.
Controlling or losing weight is not solely about willpower or calorie-counting. While calories have an impact, the nutrient density of the food may be more important. Thus, those foods high in a variety of micronutrients may also play a significant role in reducing cravings, ultimately helping to manage weight.
References:
(1) Am J Pub Health 2013 Sep 1;103(9):1604-1609. (2) Am J Prev Med.2011 Oct;41(4):434–438. (3) Am J Clin Nutr Online 2013;Jun 26. (4) N Engl J Med 2009 Feb 26;360:859. (5) N Engl J Med 2009 Feb 26;360:923. (6) Medscape General Medicine. 2006;8(4):59. (7) Clin Endocrinol.2013;78(5):700-705.
Dr. David Dunaief is a speaker, author and local lifestyle medicine physician focusing on the integration of medicine, nutrition, fitness and stress management. For further information, visit www.medicalcompassmd.com.