Nutrient Sequencing: Why Order Matters
Initial caveat: The evidence demonstrates a modulatory effect in blood glucose and insulin levels. To my knowledge, food order has not demonstrated an effect on weight loss specifically.
DEFINITIONS / TERMS TO KNOW
Post-Prandial: after eating a meal
Nutrition Sequencing: the order in which certain nutrients are eaten during a meal
Glycemic control: levels of glucose (sugar) in the blood
There has been a large body of research demonstrating how low carbohydrate meal plans impact glycemic control. The certainliy makes physiologic sense and has the body of data to back it up. However, there is also evidence that maintaining a low carbohydrate diet (even in the short term with rigorous study designs) is difficult at best (1). Hence, there has been a movement to find other ways to influence prandial (meal associated) glucose and insulin metabolism.
This is the basic idea. Let’s take a hypothetical meal that is 1/3 protein, 1/3 fat and 1/3 carbohydrate. When it comes to glycemic control and insulin levels during eating and post-prandial, does it matter which of those macronutrients we eat first, second, or last? This is where nutrition sequencing, or food order, comes into play. Theoretically, it would be easier to stick to a diet that says “eat your carbs at the end of a meal” versus “don’t eat any carbs at all”. Also, we know that consistency and longevity of any nutritional intervention is one of the most important factors for long term health.
In one study comparing a “Vegetable before carbs (VBC)” approach versus “Exchange based mealplan (EXB)” approach there were several main findings (2):
Patients in the VBC group ate significantly more vegetables and fewer fruits.
The energy ratio of carbohydrates did not change significantly in the VBC group after the intervention (54.6 to 53.4%), whereas it increased significantly in the EXB group (53.6 to 59.1%).
Perhaps more importantly, there were significantly fewer dropouts in the VBC group. Implying it was easier to sustain over the 2 year study period.
The patients in the VBC group showed increased post-meal satiety and decreased subsequent hunger when they consumed more vegetables than the EXB group. This led them to decrease their intake of carbohydrate eaten at the end of each meal.
Multiple other studies (3, 4) have demonstrated meal plans focusing on vegetables/protein/fat before carbs or simply carbs last have several effects including:
decreased glucose spike
decreased insulin spikes
decreased gastric emptying speed (think feeling fuller for longer)
longer suppression of ghrelin (the hunger hormone)
Obviously, there’s a lot more data out there, especially in animal models as well. But, theoretically, since you are reading this I assume you are human, and hence why I tend to focus on the human data.
So, in summary, food order / nutrition sequencing appears to have a significant effect on multiple metabolic factors. At the moment, the strongest data is in the diabetic and pre-diabetic population regarding glycemic control. However, the evidence regarding delayed gastric emptying and longer suppression of ghrelin would certainly suggest that this method would also help curb hunger for longer and lead to decreased total calorie intake.
Am I going to suggest this to patients who are looking to lose weight (and aren’t diabetic)? The easy answer for any doctor is, “Well, it depends”. But, I think most patients can benefit from this strategy. It seems to be sustainable, measurable and realistic. It will give you a deeper understanding of the nutrients you are taking in. So, why not? There doesn’t appear to be any harm and only the potential for benefit. I give it a solid thumbs up!
Sources
Orloff JN, Aronne LJ, Shukla AP. The challenge of meeting prescribed carbohydrate intake goals in low-carbohydrate diet studies. The American Journal of Clinical Nutrition. 2018;107(4):673-675. doi:10.1093/ajcn/nqy023
Imai et al., “A Simple Meal Plan of ‘Eating Vegetables before Carbohydrate’ Was More Effective for Achieving Glycemic Control than an Exchange–Based Meal Plan in Japanese Patients with Type 2 Diabetes.”
Shukla et al., “The Impact of Food Order on Postprandial Glycemic Excursions in Prediabetes.”
Tricò et al., “Manipulating the Sequence of Food Ingestion Improves Glycemic Control in Type 2 Diabetic Patients under Free-Living Conditions.”
