As a Registered Nutritionist and a Naturopath, I am constantly asked which diet provides the best weight loss results. A more pertinent question however is which one will work for you? Let’s explore some of the diets that are currently getting the most airtime and see which one resonates with your weight loss goals.
Chewing the fat on low carb
In the 1970’s Dr Robert Atkins revolutionised the diet industry with his low carbohydrate Atkins diet. This diet regime is comprised of four different phases, each requiring a different level of strict carbohydrate avoidance. Ultimately this leads to limiting sugars, grains, legumes, fruits and starchy vegetables, while redirecting focus to consuming red and white meats, butter, eggs, avocados, oils, nuts, seeds and non-starchy vegetables.
In terms of weight loss, this approach does have it benefits, such as reduced hunger and a positive effect on irregular blood sugar levels. However, beyond this strong focus on carbohydrates, the Atkins diet does not place limits on how much protein and fat you can consume. Understanding metabolic processes, I’d call this a ‘buyer beware’ moment, because the body (through a process called gluconeogenesis), can easily convert protein into glucose, which is the body’s preferred choice of fuel. This means the body’s supply of glucose for energy is uninterrupted throughout the diet, preventing you from burning adipose tissue (fat stores) for energy instead.
In addition to this, consuming large amounts of energy from calorie-dense fats, even if they’re ‘healthy’, negates the need for the body to dip into fat stores for fuel, as it’s already receiving enough from the diet. For these reasons, it’s important to ensure the adequate consumption of proteins and fats in a low carb diet, but to not eat too many that the body is in an energy excess rather than deficit.
The Ketogenic Diet
Alternatively, another low carb option is the ketogenic diet.
Energy 101
Normally, your body is fuelled by breaking down carbohydrates into their simplest form, known as glucose. This glucose is then taken up by the cells throughout your body, and burned to create the energy that keeps all of your systems functioning optimally throughout the day. Whilst the body can burn all macronutrients (carbohydrates, fats and proteins) for energy, carbohydrates are the easiest for your body to breakdown and utilise, leading it to preferentially burn them whenever available.
Ketogenic Eating
In contrast, a ketogenic diet adapts the body to using fat for energy, which is achieved by consuming a higher fat, moderate protein and limited carbohydrate diet.
A specific outcome of this diet is to limit the intake of carbohydrates, so the body does not have enough glucose for its metabolic needs. When this occurs (alongside consuming adequate protein), the body sources fats for fuel and converts them into compounds called ketones. It is ketones, instead of glucose, that the body then starts to use as its primary source of energy. This process is known as ketosis.
The ketogenic diet is quite different to a standard western diet, and different variations of the diet do exist. However, as shown in Figure 1 below, it is comprised of a specific balance of macronutrients, generally being:
- 50% of calories from high quality, unprocessed fats such as avocado, nuts, seeds, egg yolks, organic meat and coconut;
- 30% of calories from protein, such as fish, tofu/tempeh or organic animal protein; and
- 20% of calories from wholefood, complex carbohydrates such as leafy greens, non-starchy vegetables, legumes and low fructose fruit (such as berries).
Who can benefit from a ketogenic diet?
- Those wanting to lose weight.
- If you couple your ketogenic diet with a calorie deficit, the body will draw on your own fat stores for energy, resulting in a reduction in overall body fat.
- Those who struggle to lose weight due to insulin resistance will also benefit from ketogenic eating, as ketones do not require insulin to create energy.
- Athletes
- As a body that has entered ketosis efficiently draws energy from ingested and stored fat, the ketogenic diet can provide a constant and stable source of energy. This offers an advantage over glucose-dependant metabolism, which eventually requires regular glucose intake to sustain intense exercise performance beyond two hours.
- Individuals who prefer eating higher amounts of dietary fat;
- Those who experience digestive issues with high carbohydrate diets; and
- Individuals who respond poorly to low fat dieting.
Who might struggle with a ketogenic diet?
There are some individuals who may not easily adjust to a ketogenic diet due to conditions that limit the absorption of fats, or conversion of fats into energy. This may include individuals who experience:
- Digestive upset when consuming fat containing meals;
- Inborn mitochondrial conditions;
- Recurrent pancreatitis; and
- Gallstones or have had their gall bladder removed.
Long term effects of keto on the microbiome
Personally I am not a fan of Keto long term The evidence shows that The keto diet is often low in fibre and may harm the health of your gut microbiome, potentially increasing inflammation and reducing your concentration of good bacteria. I also get concerned with the ongoing detrimental effect sof high saturated fat intake (butter, cheese, cream, coconut, meat etc) that I see with many of my patients. I recommend you only do the keto diet under the support of your diet health professionals
Yes, you can shred with bread
On the other end of the spectrum, a diet low in fat also carries positive outcomes for weight loss. Low fat diets often focus on the restriction of fat intake to below 20% of daily calories, whilst maintaining 30% of the diet from satiating protein, and the remaining 50% from wholefood carbohydrates. The intent of this type of diet should be to encourage the consumption of naturally low-fat and high-protein foods, namely fruits, vegetables, whole grains, legumes and meats.
Whilst numerous studies have found a low fat diet to improve markers like satiety, blood sugar regulation, and weight loss,1 this diet could be considered if you don’t tolerate fats well, if you’re vegetarian, or have an increased demand for carbohydrates due to high levels of activity or exercise.
Wholefoods for Weight Loss
Pure wholefood eating is also an option, seen with the likes of the Mediterranean, Paleo or vegan diets, which all carry the common foundations of eating unprocessed foods sourced from nature. The differences then lie in the nuances, such as the promotion of fish, olive oil, and plant-based foods in the Mediterranean diet, the elimination of grains, legumes and dairy in the Paleo diet, and the avoidance of all animal products with veganism. Regardless of the variations, what I like about wholefood diets is that they epitomise nutrient density and allow you to eat the foods that you typically enjoy.
However, keep in mind these diets do not provide guidance on caloric or macronutrient breakdown, which are both keys for active weight loss. Therefore, following these diets to lose fat requires a sound knowledge of your nutritional requirements and to monitor your caloric intake. Further, you would also need to adeptly listen to your inbuilt signals of satiety and hunger, which can be easily confused by today’s increased portion sizes and any emotional or habitual attachments to food.
Also take care that you are getting enough omega 3 fatty acids, protein, calcium, zinc, iron and B12 which can often be low on these diets. You may need to supplement.
The Mediterranean diet
The Mediterranean diet is based on the traditional foods that people used to eat in countries like Italy and Greece back in the year 1960.
Researchers noted that these people were exceptionally healthy compared to Americans and had a low risk of many killer diseases.
Numerous studies have now shown that the Mediterranean diet can cause weight loss and help prevent heart attacks, strokes, type 2 diabetes and premature death.
A Mediterranean Diet Meal Plan
There is no one “right” way to do this diet. There are many countries around the Mediterranean sea and they didn’t all eat the same things.
This article describes the diet that was typically prescribed in the studies that showed it to be an effective way of eating.
Consider all of this as a general guideline, not something written in stone. The plan can be adjusted to individual needs and preferences.
The Basics
Eat: Vegetables, fruits, nuts, seeds, legumes, potatoes, whole grains, breads, herbs, spices, fish, seafood and extra virgin olive oil.
Eat in Moderation: Poultry, eggs, cheese and yogurt.
Eat Only Rarely: red meat.
Don’t Eat: Sugar-sweetened beverages, added sugar, processed meat, refined grains, refined oils and other highly processed foods.
The Mediterranean diet is one of my favourites – easy to follow every day, no faddy eating, full of all the macro and micronutrients you need.
The Vegan Diet
The vegan diet is very popular at the moment as people consider not only their own health but that of the planet.
Being a vegetarian, let alone a vegan, is not an easy choice for anyone. It’s not just a matter of removing meat from your meals. A plate of vegetables or salad doesn’t make a balanced meal and will be missing protein and other nutrients needed for proper growth and development. But armed with the right information, vegetarians can enjoy a healthy, balanced diet, and both teens and their parents can work together to make their special needs fit in with the family’s eating habits.
Guide to the basic foods
There are three key issues to consider in a vegetarian diet:
- Getting enough kilojoules for growth, as teens are still finishing their final growth phase.
- Getting enough protein to build new muscles and tissues.
- Avoiding vitamin and mineral deficiencies.
Each day you need to eat the following minimum quantities of the various food groups.
- Grains: at least 6 serves of rice, pasta, couscous, bulgar, bread, noodles, cereal or oats. A serve means 1/2 cup cooked grain or 1 slice of bread; whole grain is best.
- Vegetables: salads and sprouts: 5 serves, raw and cooked (a serve is around 1/2 cup of vegetables).
- Fruit and juices: 2 serves.
- Protein: 2 serves of cooked or canned legumes (a serve means 1/2 cup cooked beans, peas or lentils or 125g tofu or tempeh); or 2 serves of nuts or nutmeat (a serve means 1/4 cup or 30g); or 2 eggs or 40g cheese or 1 tub (200g) yoghurt; or any combination of the above.
- Calcium: 600ml milk or calcium-fortified soy drinks; in place of 300ml of milk, you could choose 40g of cheese or 1/2 cup cottage cheese or 300ml buttermilk or 1 tub (200g) yoghurt. If you don’t eat any of these calcium sources, consider a calcium supplement.
- Fats and oils: 1 tablespoon (20g) of mono- or polyunsaturated oil, mono-unsaturated spread, tahini, mayonnaise, salad dressing, peanut butter, seeds (sunflower, pumpkin, sesame), avocado or wheat germ.
The fat trap
Many girls become vegetarian because they think it will lead to weight loss – if you munch on vegetables all day, you won’t be consuming much at all. However, many popular vegetarian dishes are high in fat. For example, think of vegetarian lasagne (up to 35g of fat), vegetable laksa with fried tofu cubes (around 36g) and the humble cheese and vege flan (which can pack in 40g). Many other meat-free dishes that are deep-fried in oil, topped with a rich cheese sauce or made with buttery shortcrust pastry are also high in fat. 0 and not very healthy!
Also take care that you are getting enough omega 3 fatty acids, protein, calcium, zinc, iron and B12 which can often be low on these diets. You may need to supplement.
The hunger games
Regardless of the diet you choose, a caloric restriction is commonly required when it comes to weight loss, not just restricting food groups such as carbohydrate or fat.
In fact, the magic zone for sustainable weight loss occurs when the right macronutrient intake keeps you full and satiated, whilst a calorie deficit simultaneously leads your body to burn fat for energy .
Therefore, look for a diet that contains foods you like (and will hence stick to), but also ensure it takes macronutrient and caloric intake into consideration. This will be your best option for reaching your weight loss goals.
Weight loss: it’s more than diet
If we then look beyond food alone, factors such exercise, your environment, habits and social factors also strongly influence weight loss or gain. This means losing weight, and keeping it off long term, needs more than just a diet alone.
For these reasons I personally recommend working with a qualified Practitioner throughout your weight loss journey, so we can tailor a diet specifically to you, and ensure its satiating, wholefood based, macronutrient balanced and creates a calorie deficit. We will also then work with you to utilise specific behavioural strategies which ensure any physical, mental or emotional roadblocks to your weight loss goals are addressed. When you approach weight loss in this holistic way, it creates a foolproof plan for your success.
The best diet for you?
So what is the best diet for weight loss? Well, it’s the one you can stick to, that also encourages filling up on wholefoods, the right macronutrient balance for your body, and a level of calorie restriction.
Check out my different approaches to weight loss here https://sheenahendonhealth.co.nz/holistic-weight-loss-programmes/
I look forward to meeting you soon
References
1 Katz DL, Meller S. Can we say what diet is best for health? Annual review of public health. 2014 Mar 18;35:83-103.
2. Metagenics institute