Does body absorb nutrients less efficiently if we ingest the same amount at the same time, opposed to spreading over a larger period?

Question

I would like to understand if ingesting a certain amount of nutrients will result in different absorption from my body, depending on whether I ingest that amount spread over time or everything at once.

For example, considering all the food I eat in one day: does my body absorb the same amount of fat and protein if I eat that same amount of food all at once, compared with eating it spread by different meals? Similarly, could it be possible that my body absorbs less fat if I eat 4 hamburgers at the same time, compared with eating them spread along the day?

Answer 1

LARGE MEALS AND ABSORPTION

When consumed in usual amounts, the percent of absorbed macronutrients (carbohydrates, proteins, fats, alcohol) should not differ significantly when coming from one large or several small meals.

As an example of the composition of a single large meal, let's imagine something that fits into Acceptable Macronutrient Distribution Ranges (AMDR) in a 2,000 calorie diet: 250 g of carbohydrates, 70 g of proteins and 80 g of fats.

Most carbohydrates are digested into glucose and fructose. Glucose, when absorbed as the only carbohydrate (ingested as glucose or starch), can be absorbed at the rate 60 g/min, but the addition of fructose can increase the absorption of both together to as high as 126 g/min. When fructose is absorbed as the only carbohydrate or in the excess of glucose, it's absorption limit from one meal can be as low as 5 g or as high as 50+ grams. Certain sugar alcohols (see Table 4) (sorbitol, isomalt..) can trigger diarrhea when consumed in amounts greater than ~20 g/meal.

Virtually all ingested protein is absorbed by healthy humans (Surgery Journal). The rate of absorption depends on a type of protein: about 10 g of whey protein and 3 g of egg protein can be absorbed in one hour (JISSN).

At least 60 grams of fat consumed at once can be normally absorbed, concluding from a study in which they investigated the relationship between the amount of fat consumed and atherosclerosis.

In conclusion, the amount of macronutrients (except fructose and sugar alcohols) consumed with a single meal does not seem to significantly affect the percent of macronutrients absorbed, but it prolongs the time in which they are absorbed.

LARGE MEALS AND DIET INDUCED THERMOGENESIS

After eating one large meal, more of the consumed calories will be lost as heat than after eating several small meals:

Consuming the same meal as a single bolus eating event compared to multiple small meals or snacks was associated with a significantly higher DIT [diet induced thermogenesis]. (Nutrients, 2016)

TEF [thermic effect of food] was measured by indirect calorimetry for three hours following each meal and was found to increase systematically, in a nonlinear fashion, as meal size was increased. (Metabolism, 1984)