I do intermittent fasting and eat keto to try and lose fat while maintaining muscle. A nutritionist said to eat more carbs and fiber.

• A 41-year-old man submitted an average day of eating to be reviewed for Insider's Nutrition Clinic.
• He said he does intermittent fasting and the keto diet, and his goals are fat loss and muscle maintenance.
• A nutritionist said to eat more whole grains, fruit, vegetables, and healthy fats.
• If you'd like to have your diet reviewed by an expert, fill out this form.

Mitchell, 41, submitted his eating routine to Insider's Nutrition Clinic, where qualified dietitians and nutritionists offer advice on readers' eating habits.

He told Insider his goals are fat loss and muscle maintenance.

Mitchell said he works a desk job and exercises six days a week, doing one major muscle group and 30 minutes of cardio daily. He does intermittent fasting, eating between 10.30 a.m. and 6 p.m., and follows the high fat, low carb keto diet.

Registered nutritionist Rhiannon Lambert told Insider that intermittent fasting and cutting out carbs can have negative side effects, and they won't necessarily make it easier to reduce body fat percentage. Instead, Mitchell should incorporate more vegetables, fruit, and whole grains into his diet, Lambert said.

Mitchell breaks his fast with a protein shake and eggs

Mitchell eats his first food of the day at 10.30 a.m., drinking a protein shake and eating two egg cups made from eggs, cheese, and bacon or sausage.

Eating a high protein diet helps with muscle maintenance while in a calorie deficit for fat loss, but Mitchell's diet lacks fiber, which aids satiety and reduces hunger, Lambert said.

Intermittent fasting can help with weight loss because it's an easier way for some people to maintain a calorie deficit, but it doesn't work for everyone, she said.

"The dietary restriction seen could potentially lead to overeating, bingeing, or even eating disorders," Lambert said. "This may slow your weight loss journey as well as lead to an unhealthy relationship with food."

Mitchell eats meat and cheese for lunch

Mitchell's second meal of the day is meat, like chicken breast or thighs, steak, or ground beef with cheese and jalapenos, he said.

Lambert said he may be lacking in nutrients and energy due to low intake of carbs, fruit, and vegetables.

"Carbs are an essential macronutrient that we need to give us energy for workouts and daily life and to keep our bodies functioning optimally," she said. "Restricting them can cause fatigue, low mood, food cravings, and even nutritional deficiency."

Cutting out carbs can also lead to muscle loss while in a calorie deficit, nutrition coach Dr. Mike Molloy previously told Insider.

Lambert recommends Mitchell limit his intake of saturated fats, found in cheese and red meat, which are linked to increased risk of heart disease and stroke. Instead, prioritize unsaturated fat sources like olive oil and avocados.

These "healthy fats" and complex carbohydrates sources like whole grain rice or pasta will give Mitchell more energy for workouts and help him reach his goals, Lambert said.

Mitchell's final meal is meat with salad

For dinner, Mitchell has meat such as chicken breast, steak, or a burger patty with a salad of romaine, cheese, and ranch dressing.

Lambert said Mitchell would benefit from more food variety, so suggests swapping out some meat for salmon, beans, or chickpeas with vegetables, while also adding complex carbs and healthy fats.

"By doing this he will increase his fiber intake and plant food diversity which may be beneficial for gut health, as well as keeping him fuller longer," she said.

Mitchell takes lots of supplements

Mitchell takes 10 supplements every day including apple cider vinegar, a multivitamin, fish oil, turmeric, collagen, electrolytes, zinc, and magnesium.

However, most of these are unnecessary, especially if Mitchell eats a more balanced diet, Lambert said.

She advocates a "food first" approach.

"Following a balanced and healthy diet, rich in whole grains, fruits and vegetables, plant-based proteins, fiber, healthy fats, and adequate hydration should mean you meet the daily recommended requirements for each nutrient," Lambert said.

Certain people do fall short and need specific supplements, she said, but if not recommended by a doctor or qualified nutritional professional, you probably don't need to take them.