Dietetic Assessment and Management of Childhood Obesity

Scope and Purpose

The scope of this guideline is to provide information on the process of dietetic assessment and management of childhood obesity.  This is part of the wider guideline on the Assessment and Management of Childhood Obesity.
In addition The British Dietetic Association 2019 document also provides information on the role of the dietitian, evidence and commentary on the approach to consultations around childhood weight management.

Dietary Assessment

Aims of dietetic assessment

The aim is to establish a true picture of the CYP (child or young person’s) current and previous dietary habits, activity levels, relationship with food, an awareness of their nutrition knowledge and previous dietetic education. Developing an understanding of the CYP will help to identify the cause of overeating and barriers to change. 

A comprehensive approach to unveiling the CYP health and social background is essential. Obesity is a complex disease and not a mere imbalance of intake and expenditure. Understanding the impact of age, lifestyle, eating behaviour, food consumption, economic and social constraints takes time. It should be based on an open discussion with both the family and the child and may require several consultations.  A key point is that the future proposals should not constitute an additional burden, but rather the way to alleviate the existing one.

Areas to cover at dietary assessment

A thorough dietary assessment can ensure a good measure of their current behaviour compared to the ‘gold standard’ for healthy eating and activity.

The limitations of dietary assessment are well documented. Establishing a rapport and effective communication is likely to improve the accuracy of reporting and successful collaboration and goal setting. 

The following methods and tools for dietary assessment may be used:

• A dietary recall (last 24 hours)

• Food diaries completed prior to or between clinic appointments

• Reviewing calorie counting apps (some patients may already be using these)

• Portion size. Explore current household servings and plate sizes. Use visual guides such as the Carbs and Cals book to assess and photographs of meals.

• Establishing use of vitamin and mineral supplements

• Exploring food preferences / allergies / restrictions

• Reviewing snacking habits (in and outside of the home)

• Timing of eating (daytime and overnight)

• Meal pattern (weekday versus weekend / holidays / different households)

• Weight tracking at home (use of home scales)

• Food frequency questionnaires

• Eating and food behaviour questionnaires

• Binge eating questionnaire.

• Reviewing school menus, breakfast and after school clubs

An understanding of current activity levels can be established using:

• Step counting apps (many CYPs already measure this on their phone)

• Questions about patterns of activity (travelling to school, after school clubs, activities with family or friends)

• Discussions around access to outdoor space at home

In addition:

• Identify level of literacy and numeracy skills as this will dictate how advice is communicated and need for pictorial advice.

• Recognise financial constraints and management (as this will impact food and meal choice)

• Discuss use of food banks, supermarkets, and restaurants.

• Discuss cooking facilities and storage. Access to fridge, freezers, and ovens (a private kitchen compared to shared housing or a hotel).

It is important to not make assumptions as this can result in advice and expectations of a patient and family being unachievable. 

There can be an understandable tendency by health professionals to set an unrealistic number of targets in the first meeting and often one or two simple goals is more effective.

Dietetic Approach

There are several different approaches for dietary management and what works well for one individual and family may not be appropriate for another. To date, no one dietary approach has demonstrated superiority over another in the treatment of adolescent obesity. [1] Tailoring the advice to their needs will increase chance of success and engagement. The first line should be healthy eating and family-based lifestyle advice:  

1.   Get to know the patient

• For example; medical and social issues, mental health status, family history, current and past dietary patterns, nutritional knowledge, relationship with food, education engagement and ability, causes of obesity and barriers to change.

2.   Decide on an appropriate initial dietary intervention

• Set a couple of agreed goals.

3.   Review dietary changes, revise and build on previous dietary advice

• Provide appropriate supporting written and pictorial advice.

• Consider practical education in the community not just in a hospital setting. For example, supermarket trips and home visits.

4.   Keep repeating points 1-3

Healthy Eating

Healthy eating and portion sizes

Traditional healthy eating advice is a good start for everyone. The Eatwell Guide (plate model) can be a tool to aid discussion about food groups and the role of different macronutrients, whilst using a visual representation of everyday foods rather than technical language. Translating the Eatwell Guide into a daily meal plan explicitly showing what a balanced diet looks like is useful. Helping families to construct a family shopping list, recognise and plan balanced meals is often welcomed.

School age children may be familiar with the Eatwell Guide from school education [2]. It is important to establish a baseline knowledge and dispel any myths about healthy eating. Many families will have already received general information about healthy eating over several years and will quickly require more personalised goals. 

There should be an emphasis on including complex carbohydrates, such as whole grains, healthy fats (such as vegetable oil/sunflower oil/olive oil), adequate minimally processed fruit and vegetables and high-quality proteins. Part of the dietary education will involve a discussion about the sources of vitamins and minerals such as calcium and iron; reasons for including fibre and adequate hydration. A recommendation to avoid sugary drinks and HELN (high energy low nutrient) foods such as crisps, biscuits, sweets, and cakes and ultra-processed foods with a comment that these foods are not essential but may be enjoyable occasionally. Ideally the parent or CYP will identify potential changes to their diet themselves and be receptive to goal setting. 

In most cases, it will quickly become evident the reasons and barriers why the CYP may have not been following a healthy diet with age-appropriate portion sizes.  For example, fussy eating, strong food preferences, food insecurity and access to variety, limited family cooking skills, inadequate cooking facilities, multiple carers for the child (with different eating habits) insatiable hunger, poor boundary setting and lack of routine or education amongst others. 

Typically, in an overweight CYP the percentage of energy derived from carbohydrate is usually higher than 50-55% of their total energy intake. Sugary drinks and carbohydrate rich snacks between meals tend to significantly increase the contribution of carbohydrate in the diet as well as double carbohydrate portions at mealtimes such as pie and mash or pasta plus garlic bread.

It is also common for CYP to be having a substantial energy intake from fruit juice with families unaware of the impact this has on overall kilocalorie intake and on blood glucose and insulin levels. There should be an emphasis on having vegetables rather than fruit especially between meals. It is important to recognise that fruit contains natural sugars, and it is common for children and families to be consuming large quantities of fruit juice, fruit, and other natural sugars such as those found in syrups and honey. It is valuable to discuss interpretation of ‘5 a day’ and the pros and cons of fruits, vegetables, and natural sugars with encouragement to include low glycaemic index and nutrient rich vegetables.

Food Labelling Education

It important to provide education on food labels and how to interpret the numbers and percentages displayed.  The traffic light system used on food packaging in the UK can be confusing and the nutritional information and ingredients lists can be difficult to understand for families who struggle with numeracy. 

Portion Control

Portion control is key as people with obesity often lack satiety and have distortion of hunger and fullness sensations.  Some well-known commercial weight management programmes are not based on portion control and could allow for an excessive carbohydrate intake and therefore not always appropriate for an obese adolescent.  

A portion discussion will include number of portions of fruit and vegetables, LEHN (Low energy high nutrient) foods versus high energy low nutrient foods (HELN). The ratio of macronutrients and the percentage of energy from different food groups. Most children and families will not be familiar with weighed portion sizes, but household ‘handy’ measures and pictorial guides can be used to establish current portion sizes such as Caroline Walker Trust, British Nutrition Foundation, and Carbs and Cals documents and more [3-8]. It is important for the clinician to be mindful the published guidelines relating to CYP portion sizes and meal structure will often not be appropriate for CYP with obesity and may need to be adapted for each individual. 

A comparison of portion sizes with peers and other family members, for example, does the child have the same portion sizes as adult in the home or friends, have additional helpings and plate size, can be useful. This needs to be referenced against objective recommendations for energy.

Nutritional Supplements

Although a supplement never equates to eating the whole foods and a varied diet, an over the counter or prescriptible A-Z multivitamin and mineral supplement is recommended to help prevent deficiencies and bridge a nutritional gap for obese individuals trying to lose weight. Locked in individuals are particularly at risk of low vitamin D levels and those on metformin need to ensure adequate B12 intake. It is important to consider, investigate, identify and manage CYP with regards to nutritional deficiencies due to their dietary choices, lifestyle and possible changes whilst on anti-obesity medications {9]

Ultra-processed foods

The NOVA food classification of processed foods emphasises UPF’s (ultra-processed foods) are formulations of ingredients (typically 5 or more) mostly of exclusive industrial use, that result from a series of industrial processes [10-12]

It is common for children and young people in the UK to be consuming a diet containing a large proportion of UPF.  The National Diet and Nutrition Survey (2008-2014) found 65.4% of the total energy intake of UK children aged 4-10 came from UPF’s.  Measures of body mass index, fat mass index, weight and waist circumference found to be significantly higher in CYP consuming the highest proportion of energy from UPF’s compared with the lowest consumers. 

Over-reliance on processed foods, especially energy-dense foods high in sugar, fat, and salt, is gradually displacing home-prepared meals and the consumption of fresh fruit and vegetables in typical diets.  Common characteristics that lead to UPF’s becoming unhelpful for families when trying to reduce overall energy intake and obtain optimal intake of essential nutrients include being:

• Highly convenient, hyper-palatable, and aggressive marketing leading to consumption of large volumes compared with minimally processed foods.

• High in saturated fat, sugar, and salt

• High energy density

• High consumption leading to displacement of lower energy, nutrient dense foods.

• low in micronutrients 

• low in fibre 

Most CYP have received mixed messages about what constitutes a ‘healthy choice’. Families are often in the habit of selecting UPF’s branded as healthy options and diet foods. Unscientific claims such as ‘diet’, ‘muscle building’ and ‘low calorie’ can encourage families to purchase higher volumes of UPF’s when shopping.  These foods can displace more minimally processed and nutritious foods such as oats, fruits and vegetables, plain yogurt, beans and pulses, and unsaturated oils.

Eating alone, eating whilst watching TV, and eating away from home are contexts commonly associated with consumption of ultra-processed foods.  The following examples can help families reduce their intake of UPF’s and increase their intake of LEHN foods for healthy growth and development:

• Support with meal planning. 

• Offering more balanced alternatives to commonly consumed UPF’s commonly found in lunchboxes e.g. crisps, chocolate bars, and highly processed meats.

• Offering cookery workshops and simple recipe ideas 

• Helping to identify recurring activities associated with UPF consumption e.g. watching TV, going out with friends, and eating in the bedroom alone.

• Helping to read and interpret nutritional information on packaging.

Additional Considerations for Small Budgets

The National Child Measurement Programme (NCMP) has demonstrated the highest incidence of childhood obesity is found in the most deprived areas across the UK [13]. Additional consideration and support may be required when making food and lifestyle recommendations that may incur an additional cost. 

Table 1 - Cost considerations of common healthy eating recommendations

Additional Considerations for Insulin Resistance

A common feature of metabolic syndrome often seen with childhood obesity is insulin resistance.  In an individual with obesity, high post-prandial insulin levels are sustained, and insulin resistance becomes excessive, driving hunger but also driving carbohydrate into fat storage. The insulin signalling also damages the hypothalamus which would normally signal satiety, and the child is hungry after consuming carbohydrates, which are laid down as fat and is unable to feel full. This cyclical pattern of hunger is extremely common and is one of the factors causing severe weight gain in puberty, particularly in girls and those who are inactive or have a family history of type 2 diabetes.

There is evidence to suggest that management of the glycaemic index and glycaemic load of carbohydrate in the diet can reduce total food intake at mealtimes [14]. The glycaemic index (GI) is a ranking of carbohydrate containing food and beverages on a scale from 0 to 100 according to the extent to which they raise blood sugar and insulin levels after eating.

Foods with a high GI contain rapidly digested and absorbed carbohydrate which produces a large rapid rise followed by a fall in blood glucose in comparison to lower glycaemic index foods, which contain more slowly absorbed carbohydrate resulting in a slower rise and fall. 

The chemical and physical structure of the food, how the food is cooked and the presence of other substances such as fibre or acid will influence the GI value. The addition of protein, fat and soluble fibre can help to reduce the GI of foods. Adding fats to foods to reduce GI is not necessarily a sensible approach for managing weight, but it may be appropriate to move the emphasis away from low fat alternatives.

The physiological basis of promoting a lower glycaemic index diet is to help to reduce surges in blood glucose and thus insulin levels. Lower glycaemic index foods are helpful, but the overall glycaemic load (considering the portion size) must also be considered.

Table 2 - Recommendations for CYP with Insulin Resistance

Additional Considerations for Binge Eating

Binge eating disorder (BED) is a serious mental illness in which people experience a loss of control and eat large quantities of food over a short period of time.  

Diagnosis and Treatment 

Diagnosis of binge eating disorder relies on 2 main characteristics:

• Episodes of loss of control with eating 

• The amount of food eaten during these episodes is objectively large.

As BED is a mental illness, and the weight gain a person experiences is a symptom.  Focusing on weight loss doesn’t address the root of the illness, and the NICE guidelines specify that weight loss isn’t the intended goal of the therapies recommended to treat BED.  NICE recommends that therapy should advise against trying to lose weight during treatment through food and energy restrictions, which lead to urges to binge. Treatment should always address the thoughts and feelings that cause binges.  

Treatment for BED in children and young people is the same as treatment for adults with BED.  NICE recommends self-help treatment based around cognitive behavioural therapy adapted for eating disorders (CBT-ED) [14-16]

It may be appropriate for CYP with binge eating disorders to pause their treatment within weight management clinics and be referred on to CAMHS, although there is currently a lack of access to psychological support for binge eating in some geographical areas.

Additional Considerations for Hyperphagia

Many children and young people with obesity present with hyperphagia [17].  This is associated with a lack of satiety, preoccupation with food, food seeking behaviours, and challenging food related behaviours.  Children and young people may show little or no limit to the amount of food consumed or ask to eat again soon after having completed a normal meal. In extreme cases children may even try to get food from the bin, or eat unusual foods, for example frozen foods and pet food.  

Advice for children and young people with extreme hunger and food seeking behaviours can often focus around:

• Enhancing satiety by providing a diet surrounding high volume, LEHN (low energy high nutrient) food, and ensuring adequate hydration

• Making mealtimes last longer and increasing awareness of food consumption 

• Implementing principles of food security 

Enhancing satiety

Supporting a child distinguishing between thirst and hunger:

• Ask questions such as ‘do you feel thirsty or hungry?’

• Serve main meals with water only.
  

Increasing awareness of food consumption: 

• Sharing family meals together at regular times

• Serving foods one after another, instead of all at the same time

• Avoid serving unlimited extras in the middle of the table except vegetables without added fat or sugar. 
  

Reducing the temptation of extra servings:

• Serve meals on a smaller plate, which makes serving smaller portions more acceptable to children.

• Serving vegetables/chunky vegetable-based soup as a starter 

• Serving fruit-based desserts after a meal 

• Putting leftovers away before eating the meal being serving 

• Keeping ‘fast eaters’ at the table until everyone is finished. 

• Serving individual portioned meals instead help yourself sharing dishes

• Reducing the speed of eating:

Serving bulky and harder to chew foods such as fruit, vegetables, whole pieces of meat/fish/alternatives.

• Limit soft easy chew bite-sized foods.

• Encouraging the use of cutlery and chopsticks where possible 

• Consider serving a hot or cold drink before or after a meal while at the table to extend the mealtime experience.

• Avoid screen use during meal and snack times. 

Serving high volume, lower energy, nutrient rich meals based around to the following structure: 

• One third of a plate of lower glycaemic starchy carbohydrates

• One third of a plate of vegetables

• One third of a plate of a lean protein-based foods

Implementing the principles of food security

Evidence suggests that creating an environment with food security can help parents and young people better manage challenging food related behaviours associated with hyperphagia. 

‘No Doubt, No Hope, No Disappointment’ is a principle surrounding the idea that when a person knows what food will be served, when it will be served, with no unplanned extras between – preoccupation with food can be significantly improved.  The Prader-Willi Association New Zealand has developed several resources to help families and schools implement the principles of food security.

Additional Considerations for Fussy and Selective eating

Notable conditions where fussy and selective eating are often present:

• Autism Spectrum Disorder [18]

• Attention Deficit Hyperactivity Disorder

• ARFID

Taste sensitivity (detection and appreciation thresholds for elementary tastes) may be a factor leading to increased energy intake in children and adolescents.  A high sensitivity to bitterness, leading to the avoidance of vegetables or a fondness for very sweet food, may be the cause of increased energy intake. 

A CYP who has neurodiversity and or selective eating may have learnt safe behaviours such as a trust of packaged food, trust of colour, trust of branding and trust of appearance of processed food. Whole fresh foods are likely to be far more variable in their texture and taste and that inconsistency can be challenging.

Some of the common observations amongst selective eaters include:

• Eating less than 20 foods

• Brand loyalty

• Only eating one flavour of an accepted food

• Eating certain foods specific to context

• Demonstrating anxiety when presented with new foods

• Avoidance foods based on texture and smell.

• Avoidance most fruits and vegetables

• Dislike of mixed foods on a plate

• Preference for dry foods

The following ideas and approach can be considered when supporting a CYP who lacks variety in their diet and has strong food preferences:

• Accept introducing new foods will be a slow process.

• The CYP is likely to have had adults and professionals strongly encouraging them to try new foods and will be resistant to discussing this again initially.

• Focus on managing weight first and resolving obesity related health complications.

• Recommend an over the counter or prescribable A-Z multivitamin and mineral supplement with consideration of tolerance for tablets and syrups.

• Prioritise portion sizes and time restricted eating when setting goals

• Keep a list of their likes and dislikes and categorise into food groups/provision of macronutrients, referring to this prior making recommendations.

• Educate about healthy eating and highlight targets for the future but explain goals will be realistic.

• Discuss food chaining and introduction of similar type foods.

• Talk about stages of introduction (Putting the new food on the table, put the new food on their plate, encourage them to touch it, encourage them to lick the food, encourage them to put the food in their mouth, encourage them to chew the food)

• Discuss anxiety around new foods.

Prescriptive Interventions

Calorie and carbohydrate targets and macronutrient counting

In the initial consultation, it is usually unnecessary to explicitly prescribe a calorie target, but it is useful for the health professional to have in mind an age-appropriate energy requirement which can be compared with the child’s reported intake. 

Healthy eating and all that it encompasses including education around portion sizes, increasing diet variety and reduction of ultra processed food should be the overall umbrella for dietetic management. However, when caring for children with health complications associated with obesity it can be useful to trial more prescriptive interventions to help achieve weight loss, especially when health complications associated with obesity are detrimental to life expectancy or further deterioration of short-term health. 

There is growing consideration and awareness about the language used when talking about eating and bodyweight. The goal is for the CYP to eat well to optimise their health and wellbeing. The professionals caring for a CYP and advising about dietary changes should be mindful of eating disorders. 

Establishing a gold standard for energy requirements is problematic in CYP of average size, but particularly difficult for those of very high weight for height. This group of individuals tends to have lower levels of mobility and a high percentage of body fat. The energy expenditure is therefore lower per kg than a CYP with a similar weight centile to their height.

The energy requirements of children differ to those of adults partially because they are determined by growth and there are multiple references and method for estimating energy requirements. A combination of methods may be used to inform a recommendation however the goal is ultimately for the CYP to be consuming fewer kilocalories and a varied nutritious balanced diet.

Dietary reference values for carbohydrate cannot be made without considering the total energy of a diet and other macronutrients. The absolute dietary requirement for carbohydrate is not known but depends on fat and protein ingested. Generally, 50-100g per day prevents ketosis. 130g of carbohydrate per day for both children (over 1 year) and adults has been estimated sufficient to cover glucose to the brain. However, with low carbohydrate consumption the intake of fat and protein may then be notably high and should be considered. There is no established definition for a lower intake or tolerable upper limit for carbohydrate. The current published recommendations for carbohydrate are therefore a reference range considering total macronutrient intake and achievable dietary patterns [20-22]

Table 3: A comparison of published carbohydrate recommendations

When making recommendations for energy and macronutrients several factors should be considered:

• The CYP’s current weight compared to their ideal weight, excess weight, and body composition (percentage fat and muscle mass).

• The CYP’s physical activity level.

• An appropriate rate of weight loss.

• The urgency and benefit of weight loss to resolve health complications.

• A translation of BMI reduction of 5% over 12 weeks (also considering linear growth)

• An achievable and realistic goal for kcals and macronutrients.

• The estimated average energy requirement for their actual age and height age.

• The CYP’s current intake in terms of energy and macronutrients.

• The level of understanding and ability to measure portions, label read and macronutrient counting.

Some of the approaches to consider:

• BMR (basal metabolic rate) or REE (resting energy expenditure) calculated using their actual weight and then not adding an activity factor when deciding on a kcal target. 

• Using the EAR (estimated average requirement) for their gender and age group or TEE (total energy expenditure). However, a goal lower than the EAR may be necessary to instigate an energy deficit due to the lower levels of activity. 

• To use 75% of the EAR for their age.

• To calculate the BMR/REE of their ideal weight and add an activity factor considering their lifestyle.

There are several equations available for calculating metabolic rate with Schofield one of the most widely used but Molnar and Dietz also a particular consideration for obese adolescents [28-31]

Table 4 displays the EAR for the different ages published by SACN in 2011. These are based on an average weight CYP who is active.  The PAL factor in the calculations was increased compared to the earlier 1991 values.  An obese CYP may therefore be recommended a different target.  For example, a 15-year-old boy with a very sedentary lifestyle and NAFLD may require an 1800kcal per day target.

Table 4: Energy Requirements for Boys and Girls aged 0-18 years based on SACN 2011 [24]