As we age, our bodies change, as well as our focus, our motivation, our activity habits and our abilities. Additionally, our energy and nutrient requirements and needs are different at all different stages of our life cycle, so ‘eating for our age’ relates to making sure we meet these requirements to achieve and maintain optimal health.
In regards to energy needs, nutritional needs and metabolism, what are the main changes that occur as we age? How important is it to adjust our diets according to our age?
As we age we tend not to be as active and we are more prone to putting on fat mass and losing lean muscle mass, all of which contributes to our metabolism declining or slowing down. Because of this reason, our total energy requirements decrease as we age as well, which is also to avoid excess fat gain. However, certain nutrient requirements increase as we age since we are at greater risk of nutrient deficiencies and certain chronic health conditions and our bodies become less efficient at absorbing specific nutrients. The challenge while eating less overall is to eat more nutrient-rich foods, such as fruits, vegetables, whole grains, nuts, beans, fish, low-fat dairy products, and lean cuts of meat.
What main features of the diet do we typically need for each of these stages: teens, 20s, 30s, 40s and 50s? (specific nutrients, more energy when young, less carbohydrates when older?)
Through adolescence and our early teenage years, our bodies go through a significant growth spurt. To support the growth and development properly, this stage requires plenty of kilojoules and nutrients. During this time, nutrients such as protein, calcium, iron are particularly important. Hunger is also likely to increase since the body is growing. Therefore, it’s important to choose foods wisely to avoid excess weight gain.
The majority of our body’s growth and development will be over when we enter adulthood. We can now shift our focus on nutrition and maintaining a physically active and healthy lifestyle to reduce our risk of chronic health conditions.Through most of our adult years, our energy and nutrient requirements don’t tend to change that much, except for a couple of populations groups. Besides the obvious, gender, other groups include, pregnancy, breast feeding, athletes and chronically ill. These groups tend to have higher energy and nutrient requirements to support the extra energy demands on the body.
As we move on beyond our 50’s our energy demands decrease and thus, we must make adjustments to our diet to meet these needs. This means decreasing our energy intake but keeping our food choices nutrient dense to make sure we are getting the most from our food to support our bones, muscles and organs. During these years, fibre intake is particularly important as bowel cancer risk increases after the age of 40. Calcium is also very important to reduce risk of osteoporosis and bone fractures and breaks. Protein intake should be high to help preserve lean muscle mass and fat intake (particularly saturated fat) should be reduced to help reduce risk of weight gain, cardiovascular disease or type 2 diabetes.
In terms of carbohydrate requirements through the life cycle, this is very dependent on the fuel needs of the individual at each stage of life. Since there is currently limited data on which to base an estimate of requirements, it’s not possible to set an exact recommended dietary intake (RDI) or estimated average requirement (EAR) for carbohydrate for most age/gender groups. However, it’s important to note that carbohydrate needs are increased in pregnancy and lactation. Carbohydrate intake is also important during adolescence and teenage years since carbohydrates are the main nutrient to provide energy to bodily cells, particularly the brain, for growth and development. In most developed countries, at least 55% of total energy from a variety of carbohydrate sources is recommended. This may be higher in athletes.
Individualisation of carbohydrate intake is necessary for elderly population groups. These individuals are at risk of both malnutrition and obesity. While a high carbohydrate diet for this population group is recommended for prevention of weight gain and obesity and to optimise fibre intake, it should be recognised that some individuals may need diets higher in energy density (e.g. fats) in order to prevent malnutrition.
Does our age also affect the way we should exercise? What are your suggestions for young, mid and older people in terms of exercise type and frequency?
Ageing can have an effect on our joints, muscles and bones. Therefore, it is important to pick the right type of exercises for you and that your body can withstand. Resistance or strength training is particularly important as adults and even more so as we age. The reason being is that strength training can help maintain or increase lean muscle mass, which is important as we age to reduce the risk of falls, osteoporosis, bone fractures and breaks. Weight-bearing exercise, such as walking or weight training, is the best type of exercise for maintenance of bone mass. As we get older, balance and coordination exercises, such as tai chi, can help reduce the risk of falls, and stretching is a great way to help maintain joint flexibility.
Exercising most days of the week for at least 30 minutes in one session is considered to be preferable. Some people may choose to do more or train longer. In any case, it’s important to make sure that your body gets the recovery it needs through proper rest and nutrition.
When we are younger we are more likely to push ourselves harder to our limits. As a result, we may be at higher risk of exercise-related injuries. Depending on the type of activity you choose to engage yourself in when you are younger, it’s important to get the advice of a health professional such as an exercise physiologist or your coach to reduce risk of damaging your body. Younger people tend to have more energy as well so they may exercise or train for longer periods of time. If this is the case, it’s very important to keep the junior athlete well hydrated as the body’s thermoregulation system is still developing and provide good nutrition to support muscle growth and recovery.