You may have been told that weight management is simple. Eat less and move more. You may have also heard the phrase “calories in, calories out.” Although these ideas are not completely wrong, they are incomplete and ignore the complexity of weight management.

Weight is not simple, and the same advice does not work for everyone. The science behind weight is far more complex than what we are commonly told.

Calories and Metabolism:

Before we get into the science, let’s go through some basic concepts; calories and metabolism.

What are calories?

Calories are a way to measure energy. Food gives our body energy, and our body uses this energy to live and function. Everything we do uses energy. This includes breathing, thinking, moving, and even resting. We need a basic amount of energy just to stay alive. We need even more energy when we are active, stressed, or healing from illness or injury.

Now, what is metabolism?

Metabolism is how your body uses energy from food. Everyone has a different metabolism, naturally. This means some people use energy faster than others, even when resting.

Metabolism is influenced by genetics, sleep, stress, hormones, and body size. When we take in more energy than we use, the body stores the extra energy as fat.

Why is Weight More Complex?

Although weight loss usually requires eating less energy than the body uses, many other factors affect how the body responds.

Genetics and biology:
People naturally have different body sizes and ways of storing fat. Research shows that genetics plays a strong role in body weight and metabolism (Speakman, 2013). Even if two people eat the same foods, their bodies may respond in different ways and would be different sizes.

Hormones and appetite:
Hunger and fullness are controlled by hormones. Ghrelin increases hunger. Leptin signals fullness. These hormones are affected by sleep, stress, diet, and genetics. When they are not balanced, people may feel hungrier and less satisfied after eating (Sumithran et al., 2011).

Lifecycle changes like pregnancy, post-partum, perimenopause and menopause come with hormonal changes that also impact our metabolism and how our body uses and stores energy.

Adaptive physiology:
The body is smart and always tries to stay in balance. When weight drops quickly, the body often reacts. It may slow metabolism and increase hunger. It is important to know this a normal response, not a lack of effort or discipline (Hall et al., 2016).

Environment and lifestyle:
Our environment affects how we eat. Many people are busy and stressed. Healthy food is not always easy to access. Highly processed foods are often cheaper, faster, and more available. Family, friends and coworkers also influence eating habits.

Behaviour change:
Changing habits takes a lot time and effort. Even small changes can feel hard when life is busy or stressful.

What Actually Helps?

Nutrition and lifestyle habits matter, and food choices can support health in many ways.

Nutrition and lifestyle can affect:

• Hunger and fullness levels

• Your appetite hormones

• Cravings

• Blood sugar and energy

• Digestion

Although there are general principles of eating a balanced diet (e.g. a variety of vegetables, protein with every meal, adequate fibre, water, healthy fats), everyone has a different base-line and you need to find the strategies, supports and tools that work for you. There is not one diet for everyone and getting personalized, individualized support can help.

At RxFood we understand how complex weight is and we always look beyond the calories. We take time to understand your health history, medications, environment and your relationship with food. Learn more about the RxFood app and Care Team services here.