Introduction
The full Childhood Obesity Course is rather lengthy, and that is by design as I made it evidence-based and it takes time to discuss large amounts of evidence. However, I realize many people will not have a desire to read through the full course. Thus, I have made this shortened version. If you do not have time (or the desire) to read the full course, or if you have read it once and want a quick recap, or if you are trying to determine which portions to read in more detail, consider reading through this shorter version. Then you can refer to the full course at any point in time for clarification and further discussion of any key concepts as well as additional insights that are provided.
- The risk of obesity transcends across generations presumably due to various epigenetic mechanisms; if your parents or event grandparents had obesity then you are more likely to experience this yourself.
- When grandparents have obesity the odds of the grandchildren developing obesity increase by ~1.7 times.
- Maternal obesity increases the odds of childhood obesity by ~3.6 times.
- Paternal obesity also increases the risk of childhood obesity and adverse health outcomes.
- Prenatal smoking increases the risk of a future child having obesity.
- Preconception interventions to lose weight and improve overall health will likely benefit the future child’s health.
- I speculate that for most people with obesity aiming for 0.5-1% body weight loss weekly until losing at least 5-10% of your initial body weight and then stabilizing at a lower body weight for ~2-3 months should help maximize health benefits in a relatively time-sensitive manner with relatively low risk of unintentionally inducing harm.
- CAUTION: You should not follow any advice I provide without ensuring it is safe for you and your pregnancy according to your Ob/Gyn provider.
- There is evidence that lifestyle choices during pregnancy can influence fetal brain development as it pertains to appetite and hunger regulation.
- Maternal food intake during pregnancy can influence flavor preferences in the child.
- TIP: During pregnancy consume a generally healthy diet with a variety of flavors to help promote fetal health and preferable taste preferences. In particular, consider avoiding a lot of added sugar as this may additionally contribute to an increased risk of gestational diabetes (GDM)
- Maternal obesity during pregnancy can increase the risk of pregnancy and birth complications as well as several adverse health outcomes in childhood.
- Most of the increased child risk for long-term cardiometabolic outcomes is mediated by an increase in the child’s body fat levels; thus a lot of the risk can be mitigated by healthy habits aiding a healthy growth trajectory after the child is born.
- I discuss some of the various physiologic changes that occur during pregnancy when the mother has obesity that may increase the risk of future adverse health conditions.
- Excess gestational weight gain may not directly influence the risk of childhood obesity but will increase the risk of adverse pregnancy and birth outcomes. Additionally, excess gestational weight gain can contributed to increased inter-pregnancy weight gain, and this increases the risk of health problems with a subsequent pregnancy.
- Maternal pregnancy conditions:
- Gestational diabetes leads to a 1.45 times increased risk of the child becoming overweight; pregnancy interventions to treat gestational diabetes do not seem to decrease this risk significantly but that may potentially be due to the interventions not having great enough intensity.
- It is unclear if preeclampsia increases the risk of childhood obesity; some studies indicate a 45% increased risk but others indicate there is only a small increase in BMI seen after age 10 years.
- Antibiotic use during pregnancy has at most a small influence on childhood obesity risk; multiple infections (that would lead to antibiotic use) may increase the risk.
- Birth considerations:
- Being an only child increases the risk of obesity (presumably due to increased access to food and lack of motivation to engage in increased physical activity).
- Birth order (relative to other siblings) has a questionable association with childhood obesity based on which set of studies you examine.
- C-section delivery (vs standard vaginal delivery) does not seem to increase the risk of childhood obesity.
- Infant size:
- Low birth weight is associated with decreased muscle mass and increased body fat in adulthood. Being born small for gestational age increases the risk of future type 2 diabetes mellitus.
- High birth weight is associated with an increased risk of obesity, particularly if weight gain is not slowed after birth.
- Preterm birth is associated with an increased future risk of obesity.
- It is unclear how much of the above birth size associations with future obesity risk are due to rapid weight gain after birth; it is possible that normalizing the rate of weight gain with appropriate feeding measures will mitigate the increased future risk.
- Maternal smoking and stress can also increase the risk of future childhood obesity.
- Pregnancy interventions to treat obesity do not seem to mitigate the increased risks, but many of the interventions that have been studied are not very effective.
- Exercise interventions specifically have been shown to yield beneficial outcomes at least regarding pregnancy and birth outcomes.
- Breastfeeding can increase various flavor preferences and potentially help decrease picky eating (assuming the mother consumes a variety of flavored foods).
- Breastfeeding seems to provide at most a small benefit for future childhood obesity risk relative to formula feeding; most of the benefit that is seen in observational studies is likely due to:
- infants who are naturally hungrier being more likely to be given formula
- infants who are naturally fussier being more likely to be given formula for soothing even when they are not hungry, thus increasing the risk of excess weight gain
- Breastfeeding may allow easier responsive feeding, where the caregiver appropriately responds to the infant’s hunger and satiation cues.
- Infant formula should have relatively low protein content (this is standard) and it is important to mix the formula correctly (one study found most participants added in excessive powder).
- Complementary feeding entails the foods provided to infants once they are no longer solely consuming nutrition via breast milk and/or formula.
- Initially it is a good idea to introduce a single food, flavor, and texture at a time to ensure there are no allergic reactions and to allow your infant to experience greater variety.
- As time goes on you can mix foods more readily to ensure your infant continues to consume foods with a variety of sensory characteristics.
- In general lower protein products are ideal as excess protein consumption the first 2 years of life can increase the risk of childhood obesity.
- Specifically prepared infant and toddler products may not be ideal as they often mixed several different foods together (and thus diminish in the individual sensory characteristics they provide) and provide excess sugar.
- Baby-led weaning has some potential risks and benefits with no indication of a long-term impact on childhood obesity.
- Complementary feeding can begin any time between 4-6 months without influencing the risk of obesity relative to waiting until 6 months.
- I then provide a lot of guidance regarding complementary feeding for general health purposes regardless of obesity concerns if you are interested in reading further.
- Responsive feeding generally entails developmentally appropriate feeding practices that allow the child’s hunger and satiety cues to determine the amount of food they consume. This has been found beneficial for general feeding behaviors as well as to promote appropriate growth.
- I include a box with guidance regarding how to engage in responsive feeding with a young child. Parents can improve with this with practice.
- Picky eating generally does not impact growth to an overly significant degree but can be distressing both for the child and the caregivers; I provide a lot of advice for how to work on picky eating in the lesson.
- In general, children have to try new foods several times (up to 10-15 or more) before they may accept them. Using a positive parenting approach with modelling, potentially with associative conditioning with the first few attempts, can be worthwhile.
- Feeding styles describe different approaches to feeding a child:
- Authoritative – high in demandingness and high in responsiveness, this sets boundaries but supports child autonomy and is typically associated with the best outcomes regarding behavior and child health.
- Indulgent (low in demandingness and high in responsiveness), authoritarian (high in demandingness and low in responsiveness), and permissive (low in demandingness and low in responsiveness) are associated with worse outcomes from behavioral and child health standpoints.
- Children typically regulate their intake fairly well until they reach 1 year of age; after this point it is more important to provide appropriate portion sizes to prevent overeating.
- Rapid weight gain – an increase in weight-for-age of 0.67 standard deviations (crossing two percentile lines) in the first 2 years of life.
- This is associated with >3x the odds of childhood overweight/obesity and >2x the odds of overweight/obesity into adulthood.
- Catch-up growth – describes when infants who are born small for gestational age undergo rapid growth to “catch-up” to their peers on the growth curves.
- This aids neurocognitive development but also increases the risk of future obesity.
- It may be best to allow catch-up growth until reaching the ~30th percentile on the growth curve and then slowing the rate of weight gain towards the ~50th percentile, but more studies are needed to evaluate this potential strategy.
- Exercise is healthy at all ages; this can start as early as ~2 months of age with tummy time (where the infant is placed on the stomach periodically throughout the day, ideally adding up to ~30 minutes or so). As the infants ages you can promote increased activity by providing them space to move around and toys that move (ie, balls that roll) to help entice them to remain active.
- Various pollutants, including smoking and air pollution, can increase the risk of obesity.
- Recurrent broad-spectrum antibiotic use may contribute to an increased risk of obesity, but it is possible that the underlying infections increase the risk as opposed to the antibiotics. Antibiotics should generally not be used unless indicated but they should not be withheld due to fear of precipitating obesity.
- When children and especially adolescents have obesity there is a much higher risk that they will have obesity when they are adults.
- Obesity in childhood is associated with many health conditions; the figure below shows some of these.
Reproduced from: Calcaterra V, Verduci E, Pascuzzi MC, Magenes VC, Fiore G, Di Profio E, Tenuta E, Bosetti A, Todisco CF, D’Auria E, Zuccotti G. Metabolic Derangement in Pediatric Patient with Obesity: The Role of Ketogenic Diet as Therapeutic Tool. Nutrients. 2021 Aug 16;13(8):2805. doi: 10.3390/nu13082805. PMID: 34444964; PMCID: PMC8400548.- If children are able to transition from a state of obesity to a healthy body weight this will significantly mitigate and at times eliminate all of the increased risk for the many different potential future complications of obesity.
- Regarding appetite and obesity risk:
- Children and adolescents in general have difficulty with self-regulation around food intake as appetite and satiety ratings do not correlate well with the amount of calories that are consumed.
- When these highly palatable food options are available, this suboptimal “food environment” significantly increases the heritability of obesity.
- Children with obesity in particular have greater difficulty as they have dysregulation of their appetite and satiety hormones and they have poorer executive function (thus they have more difficulty inhibiting the drive to eat food that is available).
- These difficulties seem to increase in adolescence as both impulsivity as well as opportunities for obtaining highly palatable foods increase during this time period.
- Regular consumption of high-fat and likely other palatable foods influence the development of brain pathways to increase sensitization to these foods (thus increasing the desire for them) while simultaneously dulling the sensations resulting from their consumption (meaning more needs to be consumed for the same effect).
- I summarize some of the literature regarding psychological aspecdts of obesity in youth:
- Many youth with obesity experience stigma and a significantly decreased quality of life.
- Stigma and shame contribute to unhealthy behaviors and increased weight gain long-term.
- Motivation and success with making healthy changes is aided by parental and peer support.
- Neutral terminology (ie, “unhealthy weight” instead of “obese”) is generally preferred though individual preferences vary.
- In general, focusing on healthy behaviors rather than weight when discussing these topics with adolescents leads to healthier behavioral outcomes.
- I provide information regarding the basics of how to ideally avoid but also address psychological concerns.
- I discuss some of the literature regarding whether weight management interventions can trigger eating disorders:
- In structured weight gain prevention and weight management interventions in youth there does not seem to be a significant risk of developing eating disorders.
- Many symptoms of eating disorder pathology and overall mental health improve as a result of the interventions.
- Caveats include the facts that higher risk individuals are likely excluded from interventions, interventions may not be of long enough duration to determine long-term negative consequences, and these interventions will frequently include experts who can monitor participants for eating disorder pathology and intervene if indicated.
- In structured weight gain prevention and weight management interventions in youth there does not seem to be a significant risk of developing eating disorders.
- In the home setting without medical supervision, attempting to emulate the interventions in teaching about nutrition in a healthy and positive way will likely be beneficial; caregivers should focus on discussing and practicing healthy lifestyles and habits and avoid focusing directly on weight loss.
- Overweight and obesity are defined by BMI:
- Overweight – BMI ≥ 85% for age and gender
- Obesity – BMI ≥ 95% for age and gender
- Class II obesity – BMI ≥120% of the 95th %ile for age and gender or if the BMI is ≥35
- Class II obesity – BMI ≥140% of the 95th %ile for age and gender or if the BMI is ≥40
- Various analyses indicate that near the top of the normal range of BMI there may be increased health risks if the youth have elevated body fat levels.
- Increased levels of lean body mass seem to help mitigate some of the health complications that would otherwise occur with obesity.
- I include figures showing typical waist circumferences by age and gender.
- I include a figure showing that many different waist-to-height thresholds have been studied; this varies someway by ethnicity and more research needs to be done, but at this time:
- If the waist-to-height ratio is >0.5 this indicates potential health concerns even if the BMI is not elevated.
- A threshold of 0.46 may be more appropriate in East/Southeast Asian countries and a threshold of 0.54 may be more appropriate in Latin American countries.
- The utility of growth curves:
- When evaluating the level of obesity it is likely best to consider what the percentage of the current BMI is relative to the 95th percentile.
- Rapid weight gain, which is seen on a growth chart when the weight or BMI curves are increasing and crossing multiple percentile lines, indicates a much higher future risk of obesity; if a child does not currently have obesity but the growth curve shows that there has been rapid weight gain this is an excellent time to intervene in some way to help guide more appropriate growth.
- The adiposity rebound is the point in time when the BMI stops decreasing and begins to increase; this typically occurs between the ages of 5-7 years. When this occurs earlier this indicates a higher risk of future obesity.
- In the lesson I include a nomogram to indicate how much the risk increases based on the age and BMI at the point of the adiposity rebound.
- Perception of child weight status:
- Many caregivers are not able to accurately assess their child’s weight status and frequently will not realize that the child has obesity.
- Going to yearly check-ups so that growth can be discussed with a healthcare provider can be helpful to identify any potential health issues.
- Appropriate weight loss goals:
- There is a wide range of rates of weight loss that are typically recommended in the literature.
- In general for adults I recommend losing no more than 1% of your body weight per week; by extension I think this will also be applicable to children and adolescents who weigh ≤90 kg (~200 pounds).
- For youth that weigh >90 kg then they should lose no more than 0.9 kg/wk (~2 pounds per week). This is slower weight loss than what I recommend in adults but this makes sense when considering that children and adolescents are still growing (if not in height than at least in skeletal muscle mass and bone mineral content accrual); losing weight too quickly may prevent appropriate growth from occurring.
- Children who are successful with weight loss in the first month are much more likely to have continued success.
- If lifestyle changes do not result in any significant weight loss after one month it will be important to consider what to change to help ensure greater success moving forward.
- In this lesson I go through nutritional considerations specific to childhood obesity (as I discuss other aspects of nutrition in the Nutrition and Weight Management Course).
- Calories:
- Most people (regardless of age) are not able to estimate their calorie intake accurately.
- I include a table demonstrating how many calories children need daily from age 2-18 years based on their level of general activity.
- I include formulas that can be used to estimate how many excess calories a child is consuming to maintain an elevated body weight.
- Macronutrients:
- Consuming sufficient protein is quite helpful and can be particularly advantageous during breakfast. Protein is helpful as it increases satiety and for people losing weight it will help maintain lean body mass while body fat is lost.
- The amount of carbohydrates and fats does not seem to be very influential for weight management purposes besides ensuring a child consumes enough from the relevant food groups for general health.
- Micronutrients:
- Supplementing any of these in particular will generally not aid weight management goals.
- For children who have a more restrictive diet, either due to attempting to lose weight or due to picky eating, supplementing a low dose multivitamin/multimineral supplement may theoretically be helpful for general health.
- Food groups:
- None of the main food groups are overly influential from a weight management perspective.
- Dairy, when consumed at a level of 2-3 servings daily, does consistently influence the risk of overweight or obesity, regardless if whole-fat or low-fat options are consumed.
- Beverages:
- 100% fruit juice has several healthy properties, particularly if a child is not consuming multiple servings of fruits and vegetables daily. However, it is not very satiating. The American Academy of Pediatrics recommends no fruit juice in the first year of life, up to 4 ounces daily when aged 1-3 years, up to 4-6 ounces daily when aged 4-6 years, and up to 1 cup daily thereafter.
- Timing of nutrition intake:
- Consuming the majority of one’s calories earlier in the day may be beneficial for general health.
- Skipping meals can be particularly detrimental if it leads to significant food consumption late in the evening.
- Thus, many children and adolescents will benefit from eating regular meals throughout the day, even if they just eat small amounts at certain meals.
- For people with obesity who switch to healthier food choices and behaviors, such as letting hunger guide their eating, there is not necessary any harm in skipping meals if a person isn’t hungry assuming it does not lead to unhealthy fasting habits or excessive food consumption later in the day.
- Various diets:
- There are many different diets but none of them have been shown to be particularly advantageous for weight management, particularly in youth. Following generally healthy nutrition principles should be sufficient.
- In the lesson I provide brief guidance for any individuals who want to follow vegetarian or vegan diets.
- In this lesson I include lots of practical tips for working on feeding behaviors in children; you can read through the tips I provide in the lesson.
- General sleep recommendations include:
- 4-12 months: 12-16 hours per day (including naps)
- 1-2 years: 11-14 hours per day (including naps)
- 3-5 years: 10-13 hours per day (including naps)
- 6-12 years: 9-12 hours per day
- 13-18 years: 8-10 hours per day
- There are many reasons why obtaining sufficient, good quality sleep is very helpful for weight management goals (as well as general health). I provide several practical tips to work on improving sleep quantity and quality; you can look at the lesson to read them if desired.
- Exercise has many health benefits as well as many benefits when working on weight management goals. I discuss general exercise guidelines in Lesson 3 of the General Exercise Course and specific guidance for youth populations in Lesson 15 of that course.
- In general children with obesity can still do many types of exercise productively, but modifications may be desirable:
- They may prefer to start with strength training to build up confidence as aerobic training may prove more uncomfortable.
- Aerobic training modalities should likely be joint friendly (ie, swimming, riding a bicycle, or using an elliptical may be better than jogging due to the repetitive joint impact).
- Exercise can be harder for people with obesity; they may need to do less total work/intensity to still achieve a similar level of effort as someone with greater fitness levels. Thus, they may be working just as hard and also dealing with more discomfort even if it does not appear they are working as hard. Using relative intensity to gauge effort and guide progression will likely work much better than considering absolute metrics.
Conclusion
I hope this was informative! Please refer to the full course for further information if desired.