Preventing Childhood Obesity : From feeding pratices to dietary recommendations

Helping children achieve better nutrition by moving them away from fruit juice and sugar-sweetened beverages towards whole fruit

Michael I. Goran PhD- Children’s Hospital Los Angeles and University of Southern California, Los Angeles, USA

The prevalence of childhood obesity continues to rise with 39 million children under the age of 5 worldwide being overweight and obese in 2020. Childhood obesity is associated with a higher chance of obesity, premature death, and disability in adulthood, and also increased risk of fractures, hypertension, chronic diseases such as type 2 diabetes, cardiovascular disease, and fatty liver disease as well psychological effects. The fundamental cause of obesity and overweight is an energy imbalance between calories consumed and calories expended. Globally, there has been an increased intake of energy-dense foods that are high in fat and sugars, and a decrease in physical activity (WHO, 2021), and children are consuming more juices and sugary beverages which are high in sugars, including fructose. Indeed, in the U. S., daily fructose intake increased over the last century from just 12 g/day to about 75 g/day (Marriott, 2009).Yet, overweight and obesity, as well as their related noncommunicable diseases, are largely preventable (WHO, 2021)

Facing this challenge, the following article is a short summary of the book “Sugarproof” focusing mainly on dietary sugars and their impact on childhood obesity and related health conditions. The book presents the impacts of sugar on children’s health and well-being, addresses myths about the various types of sugars and sweeteners and suggests family-based solutions to reduce sugar consumption. Sugarproof also proposes recipes and tips to help families right-size the sugar in their diets.

Whole fruit consumption versus fruit juice, what effect and impact?

Regular sugar, or table sugar is equal parts glucose and fructose but fruit sugar and therefore fruit juices are typically higher in fructose. Although chemically identical to glucose, fructose has a very different metabolism. One of the main differences is that the body cannot use fructose as a direct source of energy. Instead, the liver takes up almost all of the fructose that is consumed, especially when it is consumed in high amounts and converts it into fat. Therefore, high fructose intake leads to enhanced liver fat accumulation, higher levels of lipids in the circulation (precursor for cardiovascular disease) and increased proinflammatory cytokine expression (Du, 2012).

As fructose is associated with fruit, it is essential to explain and differentiate the mechanism of fructose in whole fruit versus when it is consumed in concentrated and/or liquid forms, for example from fruit juice, to clarify the confusing and misunderstood aspect of this type of sugar. Indeed, whole fruit contains fructose along with glucose and many favorable nutrients like fiber. As the fructose in whole fruit is covered in fiber-rich flesh, its absorption is slowed and reduced in the body as well as its metabolism in the liver. This whole package creates a slow-release system for fructose, easing it into bloodstream and protecting the body from its negative effects.

However, fructose becomes problematic when consumed in concentrated or liquid forms such as in fruit juices, soda, and other sugar-sweetened beverages. This form of intake leads to a rapid absorption of high amount of fructose, without the presence of fiber which is responsible of slowing its absorption. This will therefore generate a rapid and direct path to the liver for conversion into fat. Yet, when it is consumed in low amounts, some of the fructose can be converted to glucose making the negative effect on liver less severe (Choo, 2018). It is therefore helpful to think of fructose effects as a continuum as shown in the Table below.

Low fructose index







High fructose index


Choo VL, et al. Food sources of fructose-containing sugars and glycaemic control: systematic review and meta-analysis of controlled intervention studies. BMJ. 2018 Nov 21;363:k4644.

Whole fruit
Optimal because:
– all the benefits of fiber and nutrient present in the fruit are get
– the fructose is slowly released during digestion, limiting its potential damaging effects on the liver
– typical serving sizes contain less sugar than in a typical serving size of juice
Blended fruit (smoothie) When blended, fiber is still retained, which helps slow the absorption of the fructose.
100% fruit juice, including fresh squeezed Juicing apples frees the fructose from the fibrous cells and eliminates the fiber in the process.
Some of nutrients might be retained but juicing essentially creates highly concentrated fructose that makes it more rapidly available for processing by the liver where it can be converted to fat.
Fruit juice drink made with high-fructose corn syrup Fructose is free in solution and easily available for rapid uptake from the gut and absorption into the blood for immediate delivery to the liver for conversion to fat.

Table 1: The Fructose Index (Adapted from Goran, 2020)

It is therefore essential to support children and accompany them to move towards fruit consumption instead of fruit juice and sugary beverages without restriction but by focusing on motivation and improving home food environment.

Internal motivation and creating a healthy home food environment are effective strategies for helping children making the healthy dietary change and moving them away from juices and towards whole fruit

Children navigate daily in a food environment containing overly sugared food products. Parents should therefore be aware that it is very difficult to remove all sugar from home and to create an overly restrictive environment. However, they could follow activities that help children reduce and minimize their intake. Sugarproof book suggests several tips to parents (cf. following paragraph) based on specific strategies: internal motivation and motivational change, creating a healthy environment and being aware of emotional eating, which when combined are more powerful and effective than implementing one strategy alone.

Internal motivation, in contrast with external motivation and that engage in a behavior for a reward, lets children feel like they are making their own choice. Parents should therefore help their children explore and develop their own reasons and internal motivations for making healthy dietary changes and ultimately learn the ability to self-regulate without the need for an external reward.

Creating a healthy, low-sugar home food environment consists in displacing unhealthy food products and providing a strong selection of healthier alternatives and making them more attractive. For example:

  • washing, cutting, and chopping fruit and raw vegetables and keeping them handy in the refrigerator for breakfasts, lunches, and snacks.
  • making pitchers of naturally flavoured water (plain or sparkling) to keep in refrigerator and easily add sliced fruit (lemon, orange, grapefruit, cucumber, etc.), or individual water bottles for schools or sports practice
  • Gradually diluting juice or other sugary drinks with plain or sparkling water and by adding more ice
  • Adding fruit (sliced bananas, strawberries, berries, etc.) to breakfast low-sugar cereal bowl instead of consuming high-sugar cereals
  • Sweeten pancakes/waffles/etc. with fruit instead of using syrup

Based on: Michael I. Goran and Emily Ventura. Sugarproof- The Hidden Dangers of Sugar That Are Putting Your Child’s Health at Risk and What You Can Do. New York (USA): Avery; 2020.

Key messages
  • The metabolism of fructose consumed from whole fruit is quite different than when consumed in liquid forms such as fruit juice.
  • The fructose in whole fruit is wrapped in fiber-rich flesh thus its absorption is slowed down and some of it can be converted to glucose and used for energy. However, fructose consumed in liquid/ concentrated forms leads to a rapid absorption of high amount of fructose, without the presence of fiber and under these conditions almost all of the fructose is taken up by the liver and converted to fat, producing pro-inflammatory by-products.
  • Promoting Internal motivation and creating a healthy home food environment are strategies that could be effective for parents to help children making the healthy dietary change and choice.
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