• A 48-year-old woman told Business Insider she's trying to limit carbs to lose weight.
• A registered nutritionist who reviewed her diet said she could actually benefit from more.
• If you'd like to submit your diet for expert advice, fill out this form.

A 48-year-old woman who wants to lose weight sent in an example of her daily diet to Business Insider's Nutrition Clinic, where qualified nutritionists and dietitians assess readers' eating habits.

The woman, Christine, was told that her efforts to cut carbs from her diet could actually be the wrong move.

Christine keeps herself active, telling BI that she strength trains three or four times a week does occasional reformer Pilates sessions too.

"I also walk the dog," she said. "I am gluten-intolerant and a busy mother of two children. I work full-time."

Registered nutritionist Sophie Trotman assessed Christine's diet and said that even though she wants to lose weight, she should consider eating more carbs and more substantial snacks.

"Christine is clearly making a big effort health-wise, especially in the context of all her existing commitments," Trotman said. "It's great to see Christine consuming a primarily whole-food diet, with good sources of protein and multiple portions of vegetables."

Christine limits her carbs

An average day of eating for Christine is:

• A quarter of an apple before a weight training session at 6 a.m.
• 1 to 1.5 liters of water before 9 a.m.
• A small handful of dry roasted nuts after the gym
• Breakfast: 2 eggs with vegetables, or turkey breast with salad
• Lunch: chicken thigh and potatoes cooked in the air fryer with olive oil and herbs, and greens
• Snacks: smoothie or homemade treat
• Dinner: a protein source with vegetables

"If I'm tired or feeling like something sweet, I'll have a homemade treat that is low in sugar and has some protein in (such as an almond meal-based brownie or tahini biscuit)," Christine said. "Or I might make a smoothie with almond milk, frozen banana, cocoa powder, and low-fat yogurt."

Christine said she's cut down on carbs hoping to lose weight.

"I am guilty of bingeing on rice crackers or potato chips once a week," Christine said. "I limit fruit to a smoothie, pre-workout carb snack, or a piece if I'm in the office."

Tip 1: Eat more carbs

It's a myth that carbs are fattening or hinder weight loss. To lose fat, you simply need to be in a calorie deficit, and carbs are in fact a valuable energy source.

Trotman said that limiting carbohydrates could be holding Christine back from getting the most from her workouts. "Carbs are the body's primary fuel source for exercise, and when you don't consume enough, you may struggle with energy levels, muscle recovery, and performance," she said.

A quarter of an apple before training likely isn't providing enough fuel, she said. Instead, Christine could try a slice of wholegrain (gluten-free) toast with nut butter, a banana, or a small portion of overnight oats.

"These will help to sustain her energy and improve workout intensity, ultimately supporting muscle growth and a more efficient metabolism," Trotman said.

She recommends Christine try adding slow-digesting carbs like quinoa, sweet potatoes, or brown rice to her lunch and/or dinner.

Tip 2: Snack on protein, fiber, and fats

While there's nothing inherently wrong with snacking on chips or rice crackers occasionally, regularly bingeing on them could be a sign that you're not eating enough to satisfy your hunger and energy needs, Trotman said.

With that in mind, she recommends Christine pair her post-workout nuts with a protein-rich option like Greek yogurt or a protein shake to boost her satiety and workout recovery.

It's good to prioritize protein but eating enough fiber and healthy fats will also help prevent cravings and urges to overeat, Trotman said. She recommends adding ingredients like avocados, seeds, and extra vegetables to meals to slow digestion and increase fullness for longer.

"If Christine still finds herself reaching for something crunchy and salty, she could try healthier alternatives like roasted chickpeas or homemade kale chips, which provide more fiber and micronutrients," Trotman said. She also recommends snack-sized bags of chips rather than bigger portions to encourage moderation.

Tip 3: Aim for sustainability

While exercise has many health benefits, too much of it, particularly high-intensity movement, can cause added stress on the body, which can cause some people to overeat for comfort. Swapping one high-intensity workout for a lower-impact activity like yoga or a walk could help, Trotman said.

She recommends Christine try to keep her stress levels down and sleep for seven hours a night — or as much as possible with two children.

Keeping her energy levels up by resting and eating enough should help Christine stick with her healthy lifestyle.

"Sustainable fat loss is about finding an approach that feels enjoyable and manageable long-term," Trotman said. "If a diet feels too restrictive, it may lead to cycles of deprivation and overindulgence, making weight loss harder in the long run."

• Hugo and Ross Turner followed a high-fat and high-carb diet, respectively, for 12 weeks.
• The identical twins both got fitter and leaner, but Hugo said he lacked energy on the high-fat diet.
• A sports scientist advised eating a balance of carbs and fats that fits with your lifestyle.

A pair of identical twins who followed different diets for 12 weeks both got fitter and leaner regardless of whether they ate high-fat or high-carb — but the high-carb twin had more energy.

Ross and Hugo Turner, 36, professional adventurers who live in the UK, have previously tested the effects of 40-minute workouts versus 20-minute workouts and compared muscle mass and chronic-disease biomarkers after eating vegan and omnivorous diets, respectively.

They asked their 25,000 social media followers what to try next, and it became clear people wanted to know whether a low-carb or low-fat diet was "better" for strength, fitness, and aesthetics.

While some people, such as keto-diet devotees, swear by going low-carb and high-fat to hit their goals, others argue that cutting fats is the route to results.

To determine whether the brothers could maintain their already high levels of strength and fitness during the experiment, rather than lose fat or build muscle, sports scientists at the UK's University of Loughborough monitored them.

While Hugo, who was on the high-fat diet, gained more muscle than his brother, he told Business Insider he performed worse and felt more fatigued during intense exercise. Ross, who was on the high-carb diet, didn't put on as much muscle but lost a little more fat and performed better in cardiovascular tests. The twins now plan to tweak what they eat depending on what expedition they're on.

The experiment was anecdotal and not large enough to prove which diet is "better." But a sports physiologist who worked with the brothers told BI it was interesting that both got fitter.

The twins added 500 calories of carbs or fat to their diets

Before the experiment, both Hugo and Ross balanced carbs and fats in their diets. For the experiment, they ate about 3,500 calories each day, 2,500 from three meals and two snacks from a food delivery service called Frive.

They didn't want to go to extremes so made their diets nutritionally different by only 500 calories a day: Hugo with more fats and Ross with more carbs.

Hugo followed Frive's low-carb meal plan and added high-fat foods such as olive oil, butter, nuts, eggs, and avocado. Meanwhile, Ross followed a "balanced" meal plan and added calories from high-carb foods such as pasta and rice, while avoiding high-fat foods.

To support their training, they also consumed 350-calorie protein shakes each day. Keeping your protein intake high is important for muscle building and repair, so was a nonnegotiable.

The Turners did similar workouts featuring a mixture of cardio and strength training using home gym equipment and rested every three days.

"We weren't perfect with our training, but we weren't perfect together," Ross said.

The low-carb and low-fat diets felt restrictive

Hugo said he found the high-fat diet "incredibly difficult" mentally and didn't feel energized or motivated.

"I just never felt good," he said. "I was eating at least six times a day and never felt full or satisfied, hence I was constantly hungry. But equally, I didn't have the crashes that I would probably associate with a higher-carb diet."

Hugo said the high-fat diet felt relatively repetitive, and he missed feeling full. Fat contains 9 calories per gram whereas carbs (and protein) contain 4. So you can eat more carbs for the same number of calories as a smaller portion of high-fat food.

For this reason, some people don't feel so full on a high-fat, low-carb diet. Others, however, find they don't feel satiated without consuming a decent amount of fat.

Ross said he missed the mouthfeel of high-fat foods but felt full. He'd occasionally have a small piece of dark chocolate, which helped with the cravings a little.

"I had my first piece of cheese in 12 weeks yesterday, and it tasted insanely good," Ross said after the experiment, and the brothers agreed that were really looking forward to eating pizza.

Endurance exercises were tougher on the high-fat diet

Before and after the experiment, the Turners measured their body compositions.

On the high-fat diet, Hugo:

• Gained 3 kilograms (6.6 pounds) of muscle
• Lost 0.3 kilograms (0.6 pounds) of fat
• Gained internal (visceral) fat: increasing from 11.4% to 12.6%
• Saw no change in his cholesterol levels

On the high-carb diet, Ross:

• Gained 1 kilogram (2.2 pounds) of muscle
• Lost 0.9 kilograms (two pounds) of fat.
• Lost internal (visceral) fat: decreasing from 11.5% to 11.1%
• Lowered his cholesterol

The Turners also tested their strength and fitness, including documenting changes in their bench presses, VO2 max, and back squats, among other exercises.

They both got better results on the strength tests by almost the exact same amount, but Hugo (high-fat) lacked energy in the cardiovascular fitness and endurance tests.

"Around 40 minutes into the running I felt like I was completely done," he said. "It felt dreadful."

Data collected by the researchers backed up Hugo's feelings: By testing their lactate thresholds while running (which involved taking blood pricks from their ear lobes every 10 minutes), they could see Hugo was struggling. Blood lactate correlates with how hard someone is working metabolically.

Ross, who was able to run for longer by the end of the experiment, noted that "carbs are very good and readily available for providing the body with energy at higher intensities."

There's no such thing as the 'best diet'

Steven Harris, a performance physiologist at Loughborough University who worked with the Turners, said it was notable that both twins saw improvements in cardiovascular fitness and metabolic health.

But the high-carb diet appeared to help Ross push himself slightly harder, possibly during his 12 weeks of training and not just the final tests.

While detailed breakdowns can be helpful for elite athletes, Harris advises the average person to eat a balance of carbs and fats that makes them feel their best and fuels their lifestyle, rather than copying what others say is the "best" diet.

Generally, if you know you're going to do a tough training session, you'll probably perform better if you've got some carbs in the tank, Harris said, which aligns with what other nutrition and sports experts have previously told BI.

While the Turners both prefer eating a balance of protein, carbs, and fat day-to-day, they said they might tweak their diets before particular expeditions going forward.

For example, ahead of high-intensity activities that raise the heart rate a lot, such as cycling, running, or kite skiing, they would up their carbohydrates beforehand. Conversely, if they were doing a walking expedition or something slower-paced, they'd choose a higher-fat diet, they said.

Correction: February 6, 2025 — An earlier version of this story misstated how much muscle Hugo Turner gained during the experiment. He gained 3 kilograms, not 1 kilogram.