One may need to adjust a client's diet due to a change in their physical activity level. Those who exercise more should increase their intake of high quality protein like salmon, grass-fed beef and lentils as to keep and build muscle and avoid catabolizing. It's also important to increase complex carbohydrates such as broccoli, sweet potatoes and quinoa. If exercising less than normal, one may need to decrease calories overall especially refined carbohydrates like sweets and juices.
As a sports dietitian, I help clients every day with adjusting their nutrition based on their activity level. When we increase our activity, we require more overall calories, especially from our body’s preferred fuel source, carbohydrates. Think of carbohydrates as the gas to our fuel tank. The more we exercise, the more we use up for energy, and the more we need to eat to refill the tank. For this reason, I recommend eating a carbohydrate rich snack about 1 hour pre-workout to fill the tank (toast with banana with peanut butter, energy bites, fruit smoothie), and including carbohydrate with the post-workout meal or snack to replenish what we used up. At mealtimes, think of filling up about 1/4 of the plate with carbohydrates when sedentary or lightly active (<60 minutes of light activity daily), 1/3 of the plate when moderately active (60 minutes of moderate intensity or 30 minutes of high intensity activity daily), and half the plate when highly active (more than 60 minutes of intense activity or double sessions). The other component that we need to prioritize in order to repair and build muscle fibers as we become more physically active, is protein. Including protein ideally within an hour post-workout and at each meal and snack throughout the day will help to meet those increased demands.
I wanted to share a case where I had to adjust a client's diet due to changes in their physical activity. This sort of adjustment is necessary when a client either exceeds the planned exercise volume or does not meet it. For example, if a client who was prescribed to train two times a week starts training four to six times a week, they will require a higher caloric intake, including more protein, carbohydrates, and fats. Similarly, if they decide to reduce their activity, the diet becomes less restrictive. The adjustments depend on the individual's goals, their exercise program, and most importantly, their energy levels.
One client came to me after starting a new exercise regimen. He had recently taken up jogging 5 times a week and noticed that the snacks he normally ate no longer kept him feeling full. I recommended he increase his protein intake at meals by adding a serving of lean meat or legumes. Protein helps provide lasting satiety to keep energy levels stable between meals. I also suggested he replace his usual snacks of chips and cookies with options higher in protein and fiber like Greek yogurt, string cheese, or nuts. These changes in his daily diet worked well to fuel his new routine while preventing him from overeating to make up for the extra calories burned through exercise.
I work primarily in eating disorders, so in recovery when a client wants to incorporate movement into their life I always adjust their eating regimen. With a focus on intuitive eating, at first it can be hard to rely solely on hunger and fullness to meet energy needs in eating disorder populations because right after exercise there are blunted hunger cues despite the body being in a prime window for nourishment and nutrient utilization. When I adjust client's eating plans to foster more exercise we focus on both the "what" and the "when", re-balancing meals and snacks and incorporating appropriate fueling being (maybe during) and after exercise. I need them to meet their energy demands while supporting recovery as well as overall health and function without them regressing into eating disorder behaviors. If the eating cannot consistently be used to balance out the exercise, then I do not recommend incorporating formal physical activity.
Tailoring Diet to Match Activity Levels I once worked with a client who was accustomed to a sedentary lifestyle but decided to incorporate regular exercise into their routine to improve their overall health. As a result, their energy expenditure increased significantly, requiring adjustments to their diet to support their newfound activity level. Drawing from this experience, I collaborated with the client to modify their meal plan, focusing on increasing their intake of nutrient-dense foods such as lean proteins, whole grains, fruits, and vegetables to fuel their workouts and aid in muscle recovery. We also adjusted their portion sizes and timing of meals to ensure they were adequately nourished before and after exercise. Over time, the client reported feeling more energized during workouts and noticed improvements in their overall fitness level, highlighting the importance of aligning diet with changes in physical activity to optimize health outcomes.