A diet rich in carbohydrates, especially sugars and products derived from refined flours, can cause, especially in sedentary people, an increase in fat and body inflammation.
This is because carbohydrates cause an increase of blood sugars (blood glucose) and a proportional insulin response: as a consequence, the excess of sugars are transformed into body fat reserves. The reason is that excess sugars, that we don’t use for energy purposes, can be converted into glycogen (sugar reserves in muscles and liver) up to a maximum of about 500g and if the glycogen reserves are full, they are transformed into fats, the reserves of which are practically unlimited!
For these reasons, several low-calorie diets, aimed at weight loss, propose a reduction in daily carbohydrate income and, in particular, distribution of them in the first part of the day, between breakfast and lunch, with a cut of carbohydrates at dinner, the time of day when we are most inactive and do not need particular energy.
Would eating carbs late at night make you fat?
To answer this question, we need to take a step back and understand what carbohydrates are and what effect they have on our organism.
The term 'carbohydrates' and the term 'sugars' mean compounds consisting of carbon, hydrogen, and oxygen bound together to form molecules like glucose or starch. The term carbohydrates and sugars can be used as synonyms, but often, in common language, they are used differently; we call carbohydrates slow-absorbing sugars, complex molecules formed by different units, while sugars are simple molecules, consisting of individual units that are digested quickly (rapidly absorbed). Glucose is a simple sugar, consisting of a single unit, while starch is a complex molecule formed by many units of glucose.
From a nutritional point of view, carbohydrates are macronutrients: nutrients that we should introduce daily and whose main function is to provide energy to our body.
Considering the three macronutrients (carbohydrates, proteins, and fats), carbohydrates should be the most represented and provide about 40-60% of daily calories. Compared to fats and proteins, carbohydrates are the nutrient we need most to support all our daily activities. Of course, the daily dose can vary from person to person, depending on body weight and lifestyle. An athlete, for example, can take about 60% carbohydrates (compared to other calories introduced), while for an overweight person, the number of carbohydrates can be reduced in favor of other nutrients.
We can easily find carbohydrates in different foods: pasta, flour, bread, baked goods, cereals and derivatives, and in many other foods. We find sugars in foods such as jams, sweets, fruit juices, or natural sweeteners such as honey or sucrose.
The latter, especially when taken in large quantities, and when we are inactive (for example in the evening), lead to a sudden increase in blood sugar and insulin, exposing us to an increased risk of gaining weight, that is, increasing our body fat reserves.
For this reason, a balanced and healthy diet, should contain a balanced low glycaemic meal and in particular a light low carb evening meal with low energy density, which, if possible, does not weigh down digestion and facilitates night rest.
From this observation comes the tendency to distribute carbohydrates differently throughout the day: a breakfast rich in sugars, often sweet, but low in protein and fat, a lunch based on pasta or rice, and a light or no carbs evening meal for dinner, based on proteins and vegetables. The typical diet of those who want to keep weight under control!
No carbs in the evening help losing weight. Right?
Several scientific studies have investigated this topic. In particular, these studies focused on the effect of low-calorie diets that involved a group of subjects consuming late-night carbs. The results are very interesting and show that consuming carbohydrates in the evening can have a positive effect, both on weight loss, and on maintaining good diet compliance over time.
Eating carbs in the evening can also promote sleep and help keep hunger under control. This is because insulin promotes the production of serotonin, which is the neurotransmitter that helps relaxation and determines a sense of satisfaction and pleasure.
When following a diet, sleeping well is fundamental: sleep loss leads to greater production of a hormone, named ghrelin, which increases hunger, and induces us to eat more, running the risk of gaining weight.
On the contrary, if you have to keep yourself shiny and active in the afternoon, a high-carb lunch could be disadvantageous, precisely because it induces relaxation and lethargy.
So... can we eat abundant sweets and carbs late at night?
Absolutely not! It would cause glycaemic peaks and a consequent increase in body fat.
If you want to lose weight and at the same time favor night rest, follow this strategy:
- Have a balanced breakfast, always inserting carbohydrates, proteins, fats, and a good amount of fiber contained in whole grains and fresh fruit. Find some examples and delicious recipes in our blog
- Make one or two snacks based on seasonal fruits and/or dried fruits such as nuts or almonds.
- Have a light lunch rich in vegetables and a vegetable protein source such as tofu or tempeh, accompanied by one or two slices of wholegrain bread, which contain low glycaemic index carbohydrates.
- If you want to enter carbohydrates for dinner choose whole foods. Wholemeal pasta or cereals in grain seasoned with tomato and/or vegetables and do not forget to always add a portion of cooked or raw seasonal vegetables. A digestible meal, but at the same time rich in fiber, which slows down the absorption of sugars and limits their blood sugar impact.
Also do not forget that to maintain your optimal weight and body composition, diet is not enough: it is essential to do regular physical activity and keep active.
Author: Francesca Deriu, Nutritionist at Minutro
Broussard JL et al., Elevated ghrelin predicts food intake during experimental sleep restriction. Obesity, 2016 Jan;24(1):132-8. Epub 2015 Oct 15.
Sofer S. et al., Greater weight loss and hormonal changes after 6 months diet with carbohydrates eaten mostly at dinner. Obesity, 2011 Oct;19(10):2006-14.