Why sugar during pregnancy can harm your baby?

by | Feb 4, 2019 | Uncategorized

IN this article I want to talk to you about the number 1 enemy of pregnancy, sugar. Too much sugar during pregnancy not only causes excessive weight gain and difficulty to lose those accumulated pounds after pregnancy, but it is also associated with health complications that directly affect your baby

Are you ready? Let’s begin!

If you continue reading I will clearly explain you once and for all the sources of “good” and “bad” sugar, an easy and practical way to know the exact amount of sugar in food you consume and how sugar consumption in pregnancy affects your child’s health already in womb and in his/her adult life.

But first I want to explain to you what carbohydrates are. Carbohydrates are long chains of sugars molecules joined together. All sugars, in order to be used by our body, must be decomposed during digestion to glucose. Once glucose arrives in the blood, blood sugar level increases.

In fact, carbohydrates are the only macronutrients that significantly increase blood sugar

Carbohydrates are found in various foods, both healthy and harmful. They are very concentrated in cereals, tubercles (ex.potatoes), fruit, vegetables and milk (and many processed products). Many women believe that it’s important to monitor the consumption of sugars in pregnancy only when they suffer from gestational diabetes (it’s a condition characterized by glucose values beyond the norm, suggestive of a diagnosis of diabetes, which is established during pregnancy in women who get pregnant weren’t diabetic).

However, research shows that even a slight increase in blood sugar during pregnancy significantly increases the risk of congenital heart defects. In another study, high levels of insulin (hormone excreted in response to high blood sugar levels) in the early stages of pregnancy were related to increased risks of the neural tube defects. This may be scaring considering that the majority of us have no idea about blood sugar or insulin levels. People often suffer from prediabetes or diabetes without realizing it.

For this reason, I believe that all women should be proactive in relation to blood sugar level during pregnancy and understand its relationship with food.

But there is more. I indicate further what are the consequences of excessive consumption of sugar during pregnancy for you but especially for your baby. You will be surprised

Apart from the effects on blood sugar, if you consume excessive carbohydrates (in the form of sugary drinks, sweets and products that contain white flour) you have “good” chances to gain too much weight during pregnancy and birth your baby way too big (macrocosmic).

In fact, women who consume a lot of refined carbohydrates, gain on average 8kg more than women who eat primarily good quality unprocessed carbohydrates and their children are born bigger with a higher percentage of body fat. Furthermore, research suggests that the metabolism of children can be permanently influenced by the mother’s diet and her excessive weight gain during pregnancy

High consumption of carbohydrates during pregnancy is also linked to increased risk of developing gestational diabetes, preeclampsia (known as increased blood pressure during pregnancy), gall bladder disease (gall bladder formation) and metabolic problems in your baby’s adult life (such as diabetes and heart disease)

That said I don’t want to tell you that you have to eliminate all carbohydrates from your diet during pregnancy, it’s not healthy nor practicable (remember that there are glucose-dependent organs such as the brain, blood cells or renal medulla that require constant glucose supply without which they cannot work).

My goal is to show you the richest in nutrients carbohydrates (those found in wholegrain foods) and to balance their consumption with other macronutrients to stabilize blood sugar levels. Considering that, you want to know for sure what foods are the richest in carbohydrates

Main sources of carbohydrates

  • Cereals: whole grain, refined and everything else made with white flour (pasta, bread, tortillas, pancakes, crackers, breadsticks, granola, breakfast cereals
  • Starchy vegetables: potatoes, sweet potatoes, pumpkin, peas, corn
  • Legumes: beans, lentils, chickpeas
  • Fruits and dried fruit
  • Milk and yoghurt (contain lactose which is a mixture of glucose and galactose)

Surely you can see that some of these foods are a good source of protein and you wonder why I included them together with pasta and bread.

Although legumes, milk and yoghurt contain proteins, they also have significant amounts of carbohydrates and therefore increase blood glucose. But they are a wise choice of carbohydrates in comparison to pasta, bread, crackers and rice because of their protein profile. Legumes are also rich in fiber that reduces the rate of absorption of carbohydrates contained in them. Foods rich in protein and fiber slow down the blood sugar rise and are therefore called carbohydrates with “low glycemic index”.

Regarding dairy products, as I mentioned before, I have included only milk and yoghurt because they contain lactose (milk sugar). Other milky products such as cheese, butter, cream and Greek yoghurt have very low lactose levels.

Taking about carbohydrates, there is also a separate category covering all processed products that contain white sugar, often hidden in many food products. The producers know that the ingredients are listed in the descending order (the main ingredient is the first on the list) so they include different types of sugar in one product to make it look less caloric in general.

Don’t be fooled, read the labels to know all the names behind which the word “sugar” is hidden

Products rich in white sugar:

  • Sugar as such: white sugar, panela, cane sugar, whole cane sugar, molasses, honey, agave, syrups (maize, maple, rice), date sugar, coconut, maltodextrin, sucrose, dextrose, fructose, maltose (any ingredient that ends with -ose, is a source of sugar)
  • Sweets/desserts: ice cream (also with yoghurt), sorbets, cakes, pastries, doughnuts, biscuits, jams, chocolate creams
  • Any snack such as biscuits,  crackers, industrial yoghurt
  • Candies and chocolate (unless it’s dark with a percentage of cocoa more than 85%)
  • Sweetened drinks: soda, fruit juice (also 100%), ice tea, vegetable drinks (almonds, oats, soy)
  • Naturally rich in sugar  foods: dried fruit (dactyl, figs, sultanas), fruit smoothies
  • Sauces: ketchup, BBQ sauce, teriyaki sauce, ketchup


Consuming too much sugar during pregnancy can be addictive and can predispose your baby’s brain to have a sweet tooth in adult life. In addition, studies have shown that diet high in sugars increases the risk of developing ADHD or similar behaviours linked to low levels of attention and impulsive behaviour. In practice, there is no study that suggests that sugars can be beneficial in pregnancy

I would like to show you a video of TED-Ed Animations that perfectly reflects the idea of where sugar can be found and how its excessive consumption affects the brain and creates an addiction equal t alcohol or nicotine. It’s brilliant!

Saying that, consider that I have never met any pregnant woman who consumed zero amounts of sugar. We don’t live in a perfect world but in a reality.

So I’ll give you some advice. If you want something sweet, remember to eat small portions, eat with mindfulness (savouring each bite) and reduce other carbohydrates in the same meal. For example, if you want to have ice cream after lunch, opt for the low-carbohydrate meal rich in fats and proteins.

How many carbohydrates should you consume during pregnancy?

Welcome to one of the most controversial topics of nutrition during pregnancy. Conventional guidelines state that carbohydrates should make up to 45-65% of daily calories. This is equivalent to 250-420 grams of carbohydrates per day for an average of 2,200-2,600 calories per day for pregnant women. There are some interesting studies that show an increased risk of childhood obesity when their mothers consumed 50% (or more) carbohydrates per day and have a correct weight.

In 2011, a study was carried out on carbohydrate consumption in 229 hunter-gatherers communities that base their diet on the acquisition and collection of food from wildlife. These communities get food by hunting animals and collecting wild fruits, without incurring to agriculture and farming. The results of the study state that the average consumption of carbohydrates in these communities is about 16-22% of daily calories. This means half or ¼ of the levels suggested by the conventional guidelines and corresponds to 90-150 grams of carbohydrates per day.  

There will be women who can tolerate more carbohydrates and some who tolerate less (which is true for any nutrient). With the exception of women with gestational diabetes or other complications, I strongly advise you to focus your nutrition on carbohydrates rich in nutrients with a low glycemic index such as non-starchy vegetables, greek yoghurt, nuts, seeds (these also have a small part of carbohydrates), legumes and berries. There is always space for carbohydrate-rich foods such as sweet potatoes, fruit and whole grains, but treat them more like a snack instead of the main meal

The simple method to calculate the amount of sugar consumed

To calculate easily the amount of sugar contained or hidden in foods you consume, I use the teaspoon method invented by Brenda Watson, an expert in nutrition and the author of Skinny Gut Diet who promotes the low carb diet.

The spoon of sugar contained in foods you eat refers not only to sugar added or naturally contained in food but also to starches that are found in carbohydrates and subsequently converted in digestive tract into sugars and absorbed in this form. Starches are therefore considered hidden sugars because you will never find them listed on labels as sugars.

There are three types of carbohydrates: starches, sugars and fiber. Starches are converted into simple sugars and are absorbed into the digestive tract as mentioned above. Sugars are absorbed, period and fiber remains resistant to digestion, passes intact to the digestive tract and you’re your microbiome.

Knowing all this now I’ll explain how the teaspoon method works to know the amount of sugars contained in foods

When you look at the label of a product you just need to identify total carbohydrates and fiber

Total carbohydrates less fiber, divided by 5 gives you the number of teaspoons of sugar contained in your food (because there are on average 5 g of sugar in a teaspoon)


This simple calculation will help you determine how much sugar is actually present in the foods you consume, even the hidden one.

Warning: the labels that also highlight the sugars don’t take into consideration the hidden sugars (for example coming from starches). Instead, the spoon does.  It is also very intuitive and it is easier to visualize the number of teaspoons than grams

Let’s take for example 42g of cooked brown rice

 Source USDA

 (32g of total carbohydrates – 1g of fiber) / 5 = 6.2 teaspoons of sugar

Brown rice is considered a healthy food but in the body is absorbed into 6 teaspoons of sugar, it’s a lot, considering that it’s only 42 grams

Let’s take another example. The classic snacks that are often served to children

Source USDA

 (38g of total carbohydrates – 1g of fiber) / 5 = 7.4 teaspoons of sugar!

The last example, the whole Greek yoghurt

Source USDA

(6.05g of total carbohydrates – 0g of fiber) / 5 = 1.2 teaspoon of sugar

As you can see, Greek yoghurt is always the best option compared to the snack. Not only does it contain less carbohydrates, but it is also an excellent source of essential proteins, minerals and fat-soluble vitamins K, A. With the addition of low glycemic fruits such as blueberries or kiwi, it’s a perfect breakfast alternative.


Modern science emphasizes the importance of a balanced maternal diet, especially in terms of the quality of carbohydrates during pregnancy and lactation, for the prevention of diet-induced obesity and alterations in the metabolism of your children.

I encourage you to give priority to foods rich in nutrients, low glycaemic carbohydrates such as non-starchy vegetables, whole yoghurt, nuts, seeds, legumes and berries. If you are not able to calculate the amount of carbohydrates you consume during the day, you can use one of the phone apps like MyFitnessPal wherein the Diary section keep track of your meals. If you want to be precise, or suspected to have gestational diabetes, in addition to routine exams, you can measure blood sugar levels at home after each meal.