Consequences of a Low-Carb Intake

Low Carb

Personal trainers need to be prepared to properly educate their clients on all things fitness and nutrition-related, given the amount of misinformation and fad diets that have become ubiquitous over the years. Among those pervasive myths that require dispelling is the insistence that low-carb intake is necessary for fat loss.

Breaking the Low-Carb Trance

“Carbs cause weight gain.”

“I don’t eat carbs – they make me feel fat.”

“I want to lose weight, so I’m going to start a low-carb diet.”

In the health and fitness industry, these statements are commonplace. We hear these and similar statements regularly from consumers, fitness clients, and Instagram influencers who may not be trained professionals (and who subscribe to the diet-culture mindset). Legitimate, certified health and exercise professionals know that this level of extreme thinking (and promoting restricting) carries consequences.

The truth is – carbs aren’t bad. Protein isn’t bad. Fat isn’t bad. What is problematic is seeing clients living their lives with such extreme rigidity that it not only detracts from their quality of life, but their goals – whatever they happen to be. Nutrition is two things: It’s a science (a well-studied, legitimized science) and it is highly personal. We must avoid being extreme on other end and work to promote reasonable balance in the dietary habits of our clients. This includes helping them understand what a healthy relationship with food is as well educating them on the consequences of a low-carb approach.

The Disconnect

When individuals think “carbs” they misunderstand that carbs aren’t just breads, baked goods, and sugar; carbs also include necessary whole grains, veggies, and fruits. These are all sources of quality nutrients the body (and brain) need to function optimally.

Second, carbohydrates are the body’s main source of energy during moderate to high-intensity exercise (fat is the primary fuel source at rest and during low intensity activities). As the intensity of exercise increases, there is a greater reliance on carbohydrates as the source of fuel. Carbs are stored as muscle glycogen and when that fuel source becomes depleted, it is the limiting factor during performance. This is not the outcome we necessarily want.

Third, when carbs are limited and/or severely restricted, acute weight loss can occur, but it is metabolic water. Carbs are stored with water, therefore, cutting them out results in an initial drop. This is also not an outcome we are aiming for when a client wishes to reduce overall body fat.

Lastly, when someone limits a macronutrient, they are likely eating fewer calories overall (because an entire food group has been kicked to the curb). The reality is – it’s just another diet – not a sustainable lifestyle practice.

The Impact of Low-Carb Commitment

When one embarks on a low-carb or no-carb journey, they will experience more than cognitive fatigue and a poor mood. Below are other consequences to become aware of.

  • Low energy
  • Decreased strength performance
  • Decreased endurance
  • Impaired cognitive focus and performance
  • Increased risk of injury
  • Decreased adaptations to exercise

What most of the U.S population is facing is not an inappropriate consumption of any one macronutrient. The real issue is an epidemic of overall poor nutrition and a considerable lack of joyful, consistent physical activity. Bottom line – carbs are not to blame, nor should they continue to be vilified because of a misinterpretation of the science. Start by educating your clients about the function of this important nutrient and what it has to offer in terms of physical (and mental) benefits.

Fitness Nutrition Coach


Dr. Erin Nitschke, NFPT-CPT, NSCA-CPT, ACE Health Coach, Fitness Nutrition Specialist, Therapeutic Exercise Specialist, and Pn1 is a health and human performance college professor, fitness blogger, mother, and passionate fitness professional. She has over 15 years of experience in the fitness industry and college instruction. Erin believes in the power of a holistic approach to healthy living. She loves encouraging her clients and students to develop body harmony by teaching focused skill development and lifestyle balance. Erin is also the Director of Educational Partnerships & Programs for the NFPT. Erin is an editorial author for ACE, IDEA, The Sheridan Press, and the Casper Star Tribune. Visit her personal blog at