Trying to lose weight. Should you go low carb or low fat? In this post, I am going to give you scientific research to find out the best approach for fat loss
Low Carb or Low Fat
Low carb vs low fat: Who wins the fight
If you are trying to lose weight, chances are you have come across the low carb vs low fat debate. Fat and carbs both have a bad reputation for making us gain weight. High carbs foods are believed to reduce the body’s insulin levels which can lead to increased hunger and overeating. Whereas high fat foods contain more calories per bite and potentially cause increased calorie consumption.
Low Carb Guy: My blood sugar and insulin levels are always low. I am a 24*7 fat burning machine.
Low Fat Guy: I am strong and powerful! Ohh and look at those veins in my forearms!! I am always pumped.
So who wins the fight?
The opinion on which one is effective between low carb vs low fat is very dividing. Some believe cutting down on fat is the most effective way to lose weight while others say low carb works the best.
In the recent past, experts have conducted several studies and observed the effect of low carb and low fat diets. So if you are trying to lose weight, should you go low carb or low fat? In this post, I am going to discuss the low carb vs low fat debate and give you scientific research to find out the best diet for weight loss.
What is a low fat diet plan?
A low fat diet is a diet in which you restrict calories coming from fat. In general, a low fat diet limits the daily fat intake to 50 grams per day. Or restrict fat intake to less than 30% of total daily calorie intake. There are different types of fat such as saturated fat, unsaturated fat, and healthy fat. Saturated fat and trans fat are found in foods like meat, butter, fast food, nuts, and oils. A low fat diet is limited in these fats and focuses on healthy fats such as whole grain, fruits, lean meat, and vegetables. Besides weight loss, a low fat diet also helps people with high cholesterol and heart disease.
What to avoid in a low fat diet:
Butter, nuts, seeds, chocolate, avocados, full fat dairy product, deep-fried food, cream, fatty meat, few plant sources like coconut and palm oil
What to eat on a low fat diet?
Whole grain, rice, pasta, Lots of green vegetables, egg whites, legumes, nonfat or low fat milk
What is a low carb diet plan?
A low carbs diet is an eating plan in which total calories from carbs are lower than the calories coming from protein and fat. This diet restricts high carbs and starchy foods such as bread and pasta. People following low carbs diet focus on eating carbs that are low in carbs density like fruits and vegetables. Carbs are the primary source of energy for our bodies. If the energy is not needed immediately after eating, it gets stored for our body to use later. Hence, limiting carbs intake can push our body to use fat instead of carbs for energy and lead to weight loss. But how do we define high carb and low carb? There is no one definition of what counts as high or low carb. One study says that carbs that have more than 45% of total calorie intake are high. Whereas below 26% of total energy intake is considered low. https://www.sciencedirect.com/science/article/pii/S0899900714003323#tbl1
However, there is no standard way of cutting down on carbs. People limit their carb intake to varying degrees to achieve their personal diet goal. A standard low carb diet has 26-44% of total daily calories from carbs. Whereas a diet that is very low in carbs will have only 10% of total daily calories coming from carbs.
What to avoid in a low carb diet:
Processed food, white rice, bread, legumes, high carb fruits, sweets, starchy vegetables, cake, refined food
What to eat in a low carb diet:
While you restrict or limit the carbs, your focus should be to include foods that are high in protein and healthy fats. Some of the food you should add to your low carb diets are:
Eggs, lean meat, fatty fish, avocados, nuts, seeds, butter, dairy products(milk, paneer), oils, soy products
Role of carbs and fat in weight loss
Out of three important macronutrients (protein, fat, and carbs), fat and carbs are used as a tool to adjust energy intake. In order to lose weight, you need to create a calorie deficit. Which means consuming less energy than you expend. Fat and carbs are both sources of calories. This is why they often get a bad reputation for weight gain. One gram of carbs provides 4 calories, while 1 gram of fat leads to 9 calories. Hence, reducing the number of carbs and fat daily diet helps you reduce calories to create a calorie deficit. Since fat has more calories than carbs, a low fat diet has become standard advice for weight loss.
Similarly, a low carb diet is also considered an effective weight loss solution. Refined and highly processed carbs are full of carbs and calories. Hence, limiting their consumption can reduce the total calorie intake and regulate blood sugar. Excess carb intake leads to fat gain which can impact your overall health as well.
Low carb vs low calorie diet
Another common approach to weight loss is limiting calorie or limiting carb intake.
A low calorie diet simply meals restricting the number of calories you eat to stay in a calorie deficit. Whereas low carb or carb counting is an eating plan where you limit the number of carbs you take in for meals. Both the method has its own pros and cons. You may enjoy one more than the other based on your eating pattern. If you choose a low calorie diet, you need to simply read labels and be mindful of the number of calories you consume in each meal. And if go with low carbs, you need to calculate daily calorie need and the percentage of calories coming from carbs. One of the drawbacks of calorie counting is that it only provides the number of calories, not the nutritional needs. So while you cut calories, you should focus on nutrients needed by your body.
Low carb VS low fat diet: what does science say
There is no one-size-fits-all answer to this. Both eating patterns have their own pros and cons. Studies have shown that both low carb diets and low fat diets help you control calorie intake and support weight loss.
One study was conducted to monitor weight loss changes among 609 participants. They have been following either a low carb diet or a low fat diet for 12 months. The low fat diet group was eating around 57 grams of fat per day. The low carb diet group was eating 132grams of carbs per day. The amount of fat and carbs was significantly lower than what they were eating before the study. The low fat diet group was asked to eat purely healthy carbs like whole grain, beans, lentils, and lean meat. Similarly, a low carb diet group was encouraged to eat foods like nuts, avocados, seeds, and fatty fish.
By the end of the study, researchers found huge variation in weight loss. Some individuals reported weight loss of 60 pounds while others gained 15-20 pounds. But the average weight loss for both groups was the same -13 pounds. https://pubmed.ncbi.nlm.nih.gov/29466592/
In the same study, metabolic syndrome and varying genetics were also taken into account. It was said those with great insulin resistance perform better on a low carb diet. This is simply because insulin demand is low. But the study found that a low carbs diet works as well for those with insulin resistance as a low fat diet.
As for genetics, it is believed that genetics play a role in how you regulate fat and carbs. The study examined the genetics of each participant. But the result did not show any difference in the amount of weight lost.
Another study on the low carb vs low fat diet effect was conducted to determine which leads to greater calorie intake. The study involved 20 adults without diabetes who were closely observed for body weight, calorie intake, and hormone levels. https://pubmed.ncbi.nlm.nih.gov/33479499/
The participants were asked to follow a plant based low fat diet for the first two weeks. Then they received a low carb diet that contained a high amount of fat. The plant based, low fat diet had 10%fat and 75% carbs. The animal based, low carb diet contained 10% carbs and 75% fat. Both the participants received around 14% protein to match total calorie requirements. It was observed that participants consumed 550-700 fewer calories per day compared to when they were on the low carbs diet. Even though this is a huge difference, they showed no difference in hunger and fullness between the two diets.
Participants lost weight on both diets. But the low fat diet showed a significant reduction in body fat. Besides that, a low fat diet led to higher blood glucose and insulin levels than a low carb diet.
The study concluded that both diets help you limit calorie intake. But a low carb diet resulted in stable insulin and glucose levels. However, the study didn’t claim if this effect can sustain over the long term.
This means both the low carb and low fat diet will help you lose weight. However, research suggests that low carb diets are more effective for short term weight loss. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC538279/
We need more scientific data to determine the long term effect of a low carb diet on weight loss.
People with obesity often suffer from many metabolic syndromes. Unhealthy carbs are responsible for causing these metabolic syndromes. These may include high cholesterol, blood sugar, and insulin resistance, and diabetes. For this reason, people with these conditions are prescribed low carb diets.
Low carb vs low fat diet for cutting
Now if you are working on getting leaner, you might think which one is better between low carb and low fat diets for cutting. Cutting is a phase that is followed by a bulking phase where you consume calories and lift weights. It is usually aimed to increase muscle mass. When you are cutting, you focus on reducing the fat gained during the bulking phase. You certainly need a diet that helps you cut down maximum fat. As many studies have pointed out, a low carb diet affects metabolism more than a low fat diet, it can lead to more fat loss. But a typical cutting diet combines intense training sessions and heavy weight lifting. Hence, it is important to have enough amount of carbs in your diet to support your exercise performance. This is because your body uses carbs as a primary source of fuel during exercise. When you are low on energy during the cutting diet, you may end up losing muscle which is not desirable for a cutting diet. One strategy you can use is to adjust your carb intake based on your training session.
You would also want to include a moderate amount of healthy fat and enough protein to maintain muscle mass.
Check out for a comprehensive cutting diet plan to achieve a leaner and shredded physique.https://docs.google.com/document/d/13nMv4O2AZwOneBhdvRNvqaRW_wDP6en1T0H4RPXOOkw/edit
Low carb and low fat combined diet
If the debate of low carb vs low fat is still confusing, you can consider a low carb and low fat combined diet. People often see carbs and fat as enemies that can hinder weight loss goals. But honestly, that’s not true. Remember that carbs and fat can always have a place in every healthy diet. A low carb and low fat combined diet may help you shed pounds while maintaining your nutrition needs. Whether on low carb or low fat diet, Just be mindful of the quality of carbs and fat you choose. Focus on whole grain carbs and healthy fats like omega-3 fatty acids. You should keep in mind that all diets will work if you stick to a calorie deficit. You can do that by either limiting carbs or limiting fat. But the ease of sticking to a diet and additional health benefits make it difficult from the other.
Low carb vs low fat diet: which one is best for weight loss?
As we discussed above, both approaches will help you lose weight. Many studies and experts have stated that it’s not low carb or low fat. Instead, it’s about choosing one that is well suited for your lifestyle and goal.
Some people on a diet can lose 60 pounds and can maintain it for two years. And other people following the same diet may lose 5 pounds only. This means one method comes with a guarantee of the same end result for everyone.
Having said that, low carb diets can have a slight edge over low fat diets. This is because low carb diets can improve metabolic health and lead to greater fat loss. One study monitored two groups of people who were on low carb and low fat diets for 16 weeks. The result found that those on a low carb diet had greater reductions in the abdominal area and total fat than those on a low fat diet. https://pubmed.ncbi.nlm.nih.gov/25527677/
Evidence also suggests that people who follow a low carb diet feel less hunger and find it easy to stick to the diet for the long run. The reason for this could be a high amount of fat and protein in the diet. Foods rich in protein and fat are more satiating because they are slow on the stomach and keeps you full for longer. One study found that people following a low fat diet have a lower level of peptide YY than those on a low carb diet. Peptide YY is a naturally occurring hormone that reduces appetite and promotes a feeling of fullness. This means low carb is less likely to make you starve. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4873405/
By limiting carb intake, the body switches from burning glucose to burning fat for energy. This makes you burn more stored fat and produce ketones. These ketones help you to achieve a stable energy level and improve mental clarity.
Many studies have been conducted to test the effect of both diets on blood sugar levels. One study in 56 people with type 2 diabetes found out that limiting carb is an effective way to control blood sugar. A low carb diet allows your body to transport sugar from the bloodstream to your cells which results in better blood sugar control. https://pubmed.ncbi.nlm.nih.gov/29882884/
A low carb diet allows you to cut down unhealthy carbs and reduce the risk of many metabolic syndromes. This may help reduce bad cholesterol, promote weight loss and improve insulin resistance. Studies also suggest that a low carb diet can improve mood, energy, and sleep. https://pubmed.ncbi.nlm.nih.gov/17228046/
Sticking to a low fat diet will also limit calorie intake and help you with weight loss. But it lacks other health benefits compared to a low carb diet. For example, a low carb diet may help you manage sugar and cholesterol and reduce the risk of developing diabetes.
Low Carb or Low Fat: Summary
So who did win in the low carb vs low fat battle? It’s the one that gives you the best result. Whether it’s a low carb diet or a low fat diet, the ideal diet for weight loss is the one your body responds the best to. As we discussed, both help you create a calorie deficit to lose weight. So choose the one that makes you feel the best after a meal.
A diet that leaves you feeling energised and full after eating is the one you should follow. Go for quality food. All the participants involved in the study were encouraged to eat the highest quality food. Whether it’s a low carb or low fat diet, as long as it’s helping you stay in a calorie deficit, it will give the results.