It is not uncommon for a new mum to find her weight has increased during pregnancy and after the birth of her first child. This can resolve as a result of increased daily activity involved in caring for the baby. At times however, the demands of motherhood, often combined with returning to work soon after the birth, can present barriers to previous dietary and physical activity habits and routines, making it more difficult to return to pre-pregnancy weight.
Understanding energy balance can help us with lifestyle and dietary changes. UK government guidelines advise against dieting during pregnancy due to possible adverse effects on the developing child, encouraging instead a healthy balanced diet with adequate exercise. Postnatal dietary advice can vary with breastfeeding or bottle feeding, and associated nutritional requirements of both mum and neonate. While the benefits of healthy weight during pregnancy are well documented, many women report increased weight after the birth of each child and progressive difficulties in weight reduction. An overview of energy balance may help to clarify some of the issues around weight management, and provide some useful tools for mums.
What is energy balance?
A regular supply of dietary energy is essential for life, and is required to fuel many different body processes involved in our Basal Metabolic Rate (BMR) needs. This is the minimum energy our body at rest needs to function effectively. These essential functions include; heartbeat, organ function, maintenance of body temperature, muscle contraction and growth. Daily energy requirements however vary widely from one individual to the next due to factors such as sex, body size, bodyweight, climate and physical activity levels.
Energy - known as calories, is obtained from the food and drink we consume, in the form of carbohydrate, fat, protein and alcohol. The amount of energy provided by these macronutrients varies: fat is the most energy dense and contains 9 kcal/gram, alcohol has 7 kcal/gram, protein 4 kcal/gram, and carbohydrates, 4 kcal/gram. Following a healthy balanced diet based on our personal calorie needs can go a long way to help us manage our energy balance and subsequent weight goals.
What is positive energy balance?
Overweight and obesity most commonly result when we consume more energy than we need; this is called positive energy balance. Despite some negative press around particular nutrients or foods, there is no single food or nutrient that causes obesity. Body weight is ultimately determined by our energy balance. Put simply, the balance between ‘energy in’ and ‘energy out’.
To maintain body weight, it is necessary to balance the calories we get from food with those we spend through BMR needs and physical activity levels (PAL). To lose weight, energy expenditure must exceed intake, and to gain weight, energy intake must exceed expenditure.
Post Pregnancy Weight Management
Obesity is the most important dietary risk factor for a range of chronic diseases, including some cancers, cardiovascular disease and type 2 diabetes. Women of childbearing age who are obese are more likely to have difficulty conceiving, and those who are obese during pregnancy are at an increased risk of complications both during and after pregnancy.
A recent study of 905 mother-child pairs undertaken in Hong Kong reported that independent of pre-pregnancy weight, women who gained more weight than the Institute of Medicine (IOM) recommendations during pregnancy had offspring with a larger body size and increased chances of adiposity (fatness), hypertension and insulin resistance (Tam et al; 2018).
How do I reduce the risk of obesity?
A busy mum struggling with increased weight has many weight loss strategies available. Help and advice can be found through contacting your doctor or dietitian. A decision to lose weight provides a good opportunity for dietary and lifestyle improvements, with good evidence showing that maintaining body weight within the healthy BMI range; eating a healthy varied diet, and participating in regular physical activity reduces weight-related health risks such as Type 2 diabetes and cardiovascular conditions.
For healthy weight loss, we should aim to lose no more than 1kg (1-2Ib) a week. This gradual reduction will increase the likelihood of sustained weight loss and help with muscle mass retention. Lifestyle benefits can include; improved sleep, more energy, increased self-esteem, and reduction in chronic disease risk.
Additional evidence-based information on weight management can be found at: www.nutrition.org.uk
Lorraine McLelland is a freelance nutritionist and UK registered dietitian based in Hong Kong. She consults independently, at Stanley Wellness Centre, & Lauren Bramley and Partners.