Low-carb, vegan, intermittent fasting: these are the three big diets that can all make the claim to be the best diet for weight loss—but which one really holds the title?
As something of diet savants, we've done the research, put ourselves to the test, talked to the experts, and have an answer: a definitive answer. So, keep reading. We're going to reveal the best diet for weight loss.
Weighing In: The for Best Diet for Weight Loss
Low-Carb diets like Atkins, keto and paleo are high-fat (~65%), moderate protein (~25%), low-carb (~10%) diets that force your body into ketosis—a metabolic state where it burns fat instead of carbs.
Pros of Low-Carb Diets for Weight Loss
Ketosis is a natural state and the benefits of following a ketogenic diet are clear. Weight loss, lowered blood sugar, improved PCOS symptoms, improved acne and for children who suffer epilepsy, a keto diet has been shown to reduce seizures.
There are other reported benefits, but they are mostly speculative. The above benefits of low-carb diets are the ones with the most scientifically-based evidence.
All good, right?
Cons of Low-Carb Diets for Weight Loss
Well, yes and no. Among the top criticisms of the keto diet are the fact that your body is running on ketones, which are a waste product produced by your liver. This is essentially like running a car on dirty fuel: you can get away with doing it for a bit, but over time, it's not good for the longevity of your vehicle.
Other criticisms include that because your carbohydrates are limited, you are limiting your consumption of healthy foods like fruits, which are packed with vital nutrients. The most common nutrient deficiencies in the keto diet include vitamins C and B, selenium, magnesium, and phosphorus—all nutrients your body needs to be healthy.
Another downside of low carb diets: because you need to eat so much fat, you're more likely to over-consume saturated fat, of which should only account for 7% of your daily calories. Saturated fat is linked to heart disease.
A high-fat, high-protein diet with little plant-based fiber can also cause issues for your digestive health. One of the most common keto-related digestive complaints is constipation.
What's more, studies show that because the liver is overburdened with fat to metabolism, existing liver problems can be exacerbated. Same with the kidneys. In fact, in addition to making kidney problems worse, keto may actually cause them.
Low carb diets have also been shown to impair thinking and judgment. The reason is simple: our brains require more carbohydrates to function properly than low carb diets allow.
Also, because low carb diets often rely on animals and animal by-products, they’re not very ecologically sound. You can eat a plant-based diet and achieve ketosis by eating high-fat plant-based foods such as nuts, seeds, coconut oil, and avocado, but one must be extra diligent about ensuring adequate protein consumption in this case.
Finally: keto can be difficult to sustain long-term. But does this mean you should avoid it?
Many people find the keto diet to be an extremely useful way to lose fat quickly and then when they've reached their goal weight, they gradually add a moderate amount of carbs back in until they are eating a diet with more balanced macros.
Learn more about healthy macro measuring for your weight loss goals here.
Other people have no problems sustaining low carb diets longer term and, with proper nutritional knowledge and guidance, have managed to enjoy a keto diet with minimal saturated fats and enough vital nutrients through low-sugar, low-carb vegetable sources.
It's not impossible to do: it just takes some practice and a whole lot of knowledge. Check out our Low-Carb Lifestyle ebook to help you start your keto diet. Filled with info and recipes, it can help you make the jump into low carb eating less daunting and more delicious.
Plant-based diets involve getting all—or at least the vast majority—of your food from plant-based sources. No meat, and no-animal by-products, which includes dairy, eggs and for many strict vegans, honey.
The plant-based diet is replete with benefits.
Pros of the Plant-Based Diet for Weight Loss
Better Nutrition. Plant-based foods like fruit, vegetables, legumes, nuts, and seeds are rich in vitamins and minerals. They contain plenty of vitamins A, C, E, and K, as well as folate, magnesium, and potassium. These vitamins and minerals aid in supporting our eyes, immune systems, muscles, skin, hearts, and brain function. Since plant-based diets lead to an increase in the number of plants you eat, your diet will include more than plenty of the vitamins and minerals necessary to better your health.
Weight Loss. Plant-based diets are rich in fiber and they lack sugary/processed foods, both go to help with healthy weight loss. Research has shown that people on plant-based diets tend to lose weight faster than those who are not. However, it is important to remember that lifestyle changes (like exercise, decreasing stress, etc.) need to be made in addition to dieting.
Lowers Risk of Various Illnesses. While plant-based foods are high in vitamins and minerals they are low in refined sugars, saturated fats, and trans fats. These are the main contributors to coronary heart disease, high blood pressure, and type-two diabetes. By lowering your intake of the contributors, you lower your risk of developing these illnesses.
The Environment. The booming meat industry is a major contributor to climate change. Not only is this unnecessarily large industry responsible for the majority of greenhouse gas emissions, but it harms the environment by cutting down rainforests to make more room to farm.
If global warming continues at the rate that it currently is, the earth will experience more natural disasters, oxygen dead-zones, and its ecosystems will become disrupted. Again, we’re not saying to avoid meat, but simply to consider reducing your reliance on it as a means to a healthier body and planet.
Cons of the Plant-Based Diet for Weight Loss
To lose weight healthfully and sustainably, your body needs to be a calorie deficit—not a nutritional deficit.
Nutritional deficits can actually slow and even prevent weight loss because the body thinks it is starving and starts storing fat and producing an influx of cortisol—the stress hormone that's linked to an increase in fat storage (especially around the belly).
A common issue with plant-based diets is that people make the switch and do so without educating themselves on plant-based nutrition.
Research shows that vegans may lack the essential nutrients since some nutrients are simply more readily available in the right quantities from meats and animal by-products. As a result, they can find themselves suffering from mild to severe nutritional deficiencies.
Here are the main micronutrients missing from purely plant-based diets:
Learn how to plug the nutritional holes in your plant-based diet. Snag our Plant-Based Vegan Guide—big savings for a limited time!
Protein and Plant-Based Diets
Adequate protein is essential to fat loss. One of the main reasons is because it helps maintain muscle mass—muscle mass that can help your body burn more fat.
Yes, you can get enough protein on a plant-based diet from food alone, but if your diet is 100% plants, it’s a lot harder.
Ask any successful vegan bodybuilder, and they'll tell you protein supplements are their BBFs. On average, you need at least 1.2 g of protein/kg of body weight if you’re sedentary, all the way up to at least 1.8 g/kg if you’ve active or even 3.3g/kg if you’re trying to bulk up and lose fat.
For example, an active female weighing 61kg (135lbs) who’s trying to lose fat is going to have to eat a whopping 110 grams of protein a day. You'd have to eat a ton of beans and rice to do that. Since a lot of plant-based forms of protein are also higher in carbs, eating that many carbohydrates per day would counteract your fat loss goals.
Learn more about plant-based protein here.
If you're looking to live a leaner, greener life but want to get the best start, grab our Plant-Based Vegan Guide. Complete with a full breakdown of plant-based macros, information on how plant-based eating, tips and 40 recipes (including desserts!), snagging this affordable and educational ebook is the biggest favor you can do toward your long-term plant-based weight loss goals.
Technically, intermittent fasting is not a 'diet' in the popular sense of the word, since it does not restrict what you eat, merely when you eat. However, it is a widely-praised eating paradigm that can yield incredible fat loss, so we want to include it in our best diets for weight loss debate.
Intermittent fasting involves using short, sustainable periods of fasting combined with shorter periods of eating to lose fat, gain muscle, balance hormones, increase productivity and basically live a longer, happier life. During these periods of fasting, you can drink water, black coffee or tea, but you cannot eat or drink anything with caloric value or anything that can affect your blood sugar levels.
While some types of IF involve not eating for 24 hours, the type of IF more commonly used 16:8 method, meaning fasting periods are around 16 hours long and eating windows are within a spread of 8 hours. Which exact hours you choose to fast and eat will depend on your lifestyle and personal preferences, but the majority of fasting is done while you are asleep.
For example, if you are a night owl and rarely go to sleep before midnight (or later), your fast could start around 10 pm and go until 2 pm the next day. If you are getting decent sleep, this only gives you approximately 6 hours when you’re awake the next day and not eating. That’s it.
Another example: you go to bed each night at around 9 pm. In this case, you could stop eating at 6 pm and eat the next day at 10 am. Again, you get to pick your fasting and eating slots to suit your life.
Pros of Intermittent Fasting for Weight Loss
Intermittent fasting works on three levels to help you lose fat, build muscle and feel better.
Your Body on IF
Fasting has been used to enhance spirituality for centuries, but it wasn't until the turn of the 20th century that doctors began to note the physical perks of IF. Since then, the method has been prescribed by healthcare professionals and utilized by people looking to build muscle and lose unhealthy body fat.
It may seem counterintuitive, but the human body actually flourishes with intermittent fasting. A lower body fat percentage and increased muscle health results in a decreased risk of heart disease, diabetes, and cancer, while IF has also been shown to promote healthy hormonal balance, and has even been credited with increasing longevity.
Much of these miracle-like occurrences are actually just the result of how IF bolsters your cellular health and, as a result, your metabolic health.
IF and Cellular Health
IF has been shown to reduce inflammation as well as oxidative stress, which in turn bolsters the quantity and quality of cellular mitochondria (the parts of cells that convert fats, proteins and sugars into the chemical energy the body uses to live) while simultaneously stimulating autography (the process of cellular self-cleansing and apoptosis or ‘cell death’). This is good because when a cell doesn't die when it’s supposed to, it can begin to grow at an uncontrolled rate, developing into potentially cancerous tumors.
Translation: IF helps your cells look and feel healthier and younger and run more effectively and, therefore, you look and feel healthier and younger.
What’s more, by positively influencing the cellular and metabolic systems, IF strengthens the whole body, protecting it against disease as well as bolstering the neuron responses that usually lag with aging. As a result, IF is also credited with improving brain health and protecting against degenerative brain diseases.
IF and Insulin
Intermittent fasting can also help regulate insulin response. Insulin's function is to encourage the storage of energy. When we eat, our insulin levels increase and fat are held, untouched, in our fat cells as our body uses the glucose in the bloodstream. During this stage of insulin influx, the fats cannot leave the fat cells. However, when you fast, you lower insulin, thereby increasing lipolysis—the rate of fat breakdown. And since your cells are healthier, this can and will happen more effectively and efficiently.
IF and Muscle
While IF helps you lose fat, it has been shown to also help you build muscle. This is in large part due to the fact that IF can increase human growth hormone by up to five times. In addition to further fueling the fat burning process, a higher level of human growth hormone will also support major muscle gains.
IF and Hormones
The rebalancing of hormones is one of the main reasons IF works for so many people who have been failed by conventional healthy eating advice. It’s not that these traditional methods are wrong, but that hormonal changes within your body have rendered them useless for you.
Just like one pair of shoes won't fit you from childhood to adulthood, neither will one diet. You change. Men and women go through hormonal changes (women go through SEVEN) and intermittent fasting can help your reset and readjust your hormones so that your metabolism runs at prime so you can lose weight.
IF and Food Freedom
There is nothing that you can't eat when you IF. You can eat carbs. You can eat meat. You can eat a plant-based diet and do IF. You can eat a low-carb diet and do IF, which will definitely help you lose fat even faster—albeit, the double dose of heavily restricting what you eat and when you eat may be too much for many people to sustain long-term. And, you'd have to be extra, extra careful about nailing your macronutrient intake.
Or, you can just eat a balanced diet with no food group restrictions and do IF. However, even though IF will rev up your metabolism, you do have to eat mostly healthy, most of the time.
You have to know your macros, and hit them, for the most part. Again, here's that article on macro measuring made easy. Remember: no matter what diet or eating paradigm you follow, the best diets for weight loss always involve eating mostly healthy, clean foods.
You can eat a healthy 2,000 calorie a day diet and lose weight. You can eat an unhealthy 2,000 calorie a day diet and have little to no fat loss.
The point is: eat well.
Grab our best-selling Fast & Furiously Fit ebook to get a solid handle on IF so you can start with total confidence, and amazing results. Macronutrient breakdowns, tips, recipes and MORE included.
THE ANSWER: The Best Diet for Weight Loss
All of these diets, when done correctly and with a focus on proper nutrition, can help you lose weight. However, the absolute best diet for weight loss is obvious: it’s the one that speaks to you.
If you’re lukewarm about meat, then you could probably rock a plant-based diet. If you could debone a chicken from across the table, then keto might be the ticket to weight loss—even if low carb eating is a short-term solution that serves a step toward a longer-term goal of lower carb eating in general.
If you want to be able to eat with no food restrictions, then IF is likely a good pick. Or, as we said, you can combine IF with plant-based or low-carb eating and accelerate results.
The point is this: when you don’t feel burdened by a healthy diet, it is easier to stick with, and a healthy diet that’s sustainable for you is the best diet for weight loss.
What do you think is your best diet for weight loss? Share in the comments!
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