March-April, 2023

UNDEREATING MAY BE SABOTAGING CLIENT GOALS

PROTECTING OUR METABOLISM FOR BODY COMPOSITION CHANGES

By Angela Wallace, MSc, RD

IT COMES TO LOSING WEIGHT, MANY PEOPLE DO NOT KNOW WHAT EATING “ENOUGH” FOOD LOOKS LIKE.

I find this particularly challenging with women. Men are often encouraged and expected to eat substantial amounts of food, while women are told the opposite. Women often experience feelings of guilt for eating larger portions and are more likely to follow restrictive diets. In fact, most North American dieters each year are women (over 55 percent).

It is typical for women to avoid carbohydrates and undereat in the hopes of quickly reaching their weight loss goals. When doing a quick weight loss search on the internet, you will see tons of 1200 calorie meal plans for women trying to lose weight. I would argue that 1000-1200 calories are the daily caloric needs of a toddler, not a grown adult woman. In fact, not eating enough can do the opposite of helping someone to lose weight. It can hinder weight loss, fat loss, muscle gain, and decrease energy levels. Undereating can be just as problematic as overeating when it comes to weight loss and body composition.

To support weight loss, the client must be in a caloric deficit. However, it is important to consider what amount of deficit will help support your client in achieving maintainable weight loss. Typically, a maintainable deficit ranges between 250-500 calories per day. When I work with women looking to lose weight, I try not to create a deficit of more than 350-400 calories, as I often find that going beyond that will lead to shifts in their metabolism.

Undereating shifts our metabolism

Our bodies are subject to homeostatic control, meaning our body always wants to be in a state of balance where it feels safe, comfortable, and can function optimally. An example of the body’s homeostatic control regulation is body temperature. If our core temperature rises, our body will begin to sweat to release the heat from our core and cool our internal temperature. This homeostatic control also influences our metabolism, where large deficits in calories can elicit changes in our metabolism. Metabolism can be defined as the sum of all chemical processes that take place within your body to sustain life. To drive these processes your body requires fuel, aka food. When chronically undereating, the body will slow down all processes to stay as efficient as possible, meaning fat loss is not a main priority.

Alternately, as you exercise and begin to gain muscle, your metabolic rate (or metabolism) will increase. However, if you do not meet this increased energy demand by eating enough food your metabolism will slow down and try to use what it is given while conserving energy and fat.

In addition to shifts in metabolism, undereating can create shifts in hormone production. When you do not eat enough your body reduces sex hormones, thyroid hormone, and increases production of stress hormones, such as cortisol. Overtime, these hormonal shifts can lead to water retention, difficulty losing weight, increased fat mass, and health concerns. It also influences your hunger hormones, creating increased appetite and less indication of fullness.

Bottom line

When you are undereating and in an extreme calorie deficit (more than 500 calories per day) your body will begin to prioritize what is needed for survival rather than rebuilding muscle. So even if a client is working hard exercising and following a calorie deficit, they may not be seeing any real changes to body composition, especially when it comes to muscle gain. When not fueling your body properly it also becomes difficult to train, the intensity will feel more challenging than it is because they are underfed.

Some symptoms associated with undereating:

• Difficulty sleeping

• Low energy levels

• Exercise feels really challenging (more than usual)

• Mood swings

• Brain fog, confusion

• Depression/anxiousness/change in mental state

• Constipation

• Hair loss

• Low sex drive

Working with a client who wants to lose weight

Make sure they are eating enough to fuel their daily activities and the workout regimen they are hoping to follow. If they are experiencing any of the symptoms above, have them re-evaluate what they are eating. They may benefit from additional nutrition support, get them to seek guidance from a nutrition professional. This is particularly important if their undereating is intentional and concerning.

There are general ways to calculate caloric needs, however it is important to assess other factors including the client’s level of stress, daily work activities, physical output, and sleep. Their lifestyle will contribute to their total caloric needs.

Remember, the number of calories each person needs varies and finding the right amount to fuel their body can take some time. Encourage your clients to experiment with types of foods and quantities to help them feel their best. And remind them that undereating will not fuel their body or help them achieve maintainable body changes.

Angela Wallace is a registered dietitian, canfitpro personal trainer and Pilates instructor. She specializes in nutrition for women and children. Angela loves helping women feel their best, from the inside out. Follow her on IG @nutrition.for.families