The Best (science backed) Diet For Weight Loss
Without doubt, when it comes to weight loss, your diet is the most important thing to get right. But it's this area where most people fail.
And I get it, the problem is that there's so much information out there all giving you difference advice. This is where the frustration and overwhelm can set in. Who to believe, what diet is best? Keto, intermittent fasting, paleo, DASH, Slimming World.
But the funny thing is, whether it's fasting, keto, or Weight watchers, research has consistently shown us the reason why they can work is because they all follow the same principle of finding a calorie deficit. A calorie deficit is when you burn more calories t than you eat through food. Although each one of these diets may all have their own advantages, and disadvantages, the principle of getting you into a calorie deficit is what leads to any success.
What to take from this?
It doesn't matter what diet you follow providing you find a calorie deficit, so look to find something you can stay consistent with and enjoy!
However, there are still a number of things you want to get right to optimise your diet for weight loss, especially if you want to keep the weight off. These start with your number of calories, protein, fat and carbohydrates you're eating.
Finding the right Calorie Deficit For You
Firstly, you need to find the right calorie deficit for you to maximise your fat loss and minimise any down-regulation ('damage') to your metabolic rate. You also want to do what you can to spare muscle mass as this can reduce any reduction in your metabolic rate and increasing your carbohydrate storing capacity.
This means you can eat more carbohydrates :)
Research has shown us that a gradual calorie reduction is better for reducing fat mass, preserving lean mass and metabolic rate compared to rapid weight loss.
As a guide, I recommend a weekly weight loss of between 0.5-1% of your bodyweight per week. Someone with a higher body fat % should expect quicker changes.
Example - 80kg Person
A target rate of weight loss will be between 0.4-0.8kg per week, based on 0.5 - 1% of bodyweight per week.
0.5% of bodyweight = (80/100 x 0.5) = 0.4kg per week. 1% of bodyweight = (80/100 x 1) = 0.8kg per week.
How do you calculate your calories
1. Test - The most accurate way is by using a Resting Metabolic Rate test, which measures how many calories you are burning, making it easier to provide you with an accurate set of calories and macronutrients.
2. Using our online kcal and macro calculator - Calorie calculators provide a starting point, but treat these with caution as they are notoriously inaccurate
Whichever method you choose to use, you will still have to make some adjustments to your plan based on your progress.
Next up is protein.
Calculating your protein targets
Protein is the macronutrient that is most important for individuals who are looking to lose weight. High protein diets consistently show improvements in weight loss and body composition.
Why is protein important for weight loss ?
It helps to spare muscle mass when in a calorie deficit - as mentioned earlier, you want to do what you can to help keep as much muscle as possible when in a calorie deficit and protein is key for this.
It's more satiating than carbs and fat - meaning it will help to control hunger levels, making it easier to stick to your diet.
It has a higher TEF - the thermic effect of food is the number of calories required to digest, absorb and process the nutrients in your food. Protein has the highest TEF of the macronutrients, meaning you will burn more calories digesting it.
How much protein do you need to lose weight?
A protein intake that is around 1.6-2g/kg (0.6-1g/lb) of target bodyweight is a good starting point for people looking to lose weight, with the upper end being more beneficial for those who are also trying to retain muscle mass.
For our 80kg person with a target body weight of 70kg, a Protein intake of 112-140g per day would be a good target.
Calculating your carbohydrate and fat targets
The next thing to look at are carbs and fat. The amount of carbs and fat you need will be dictated by how many calories you have left after you've taken into account your protein intake. Contrary to popular belief, it doesn't really matter if you go low carb or low fat if your goal is weight loss.
A recent research review discovered that a low carb diet was no more successful in weight reduction than a low fat diet, as long as protein consumption was matched. This is the reason when weight loss is the goal, the focus should be finding a ratio of carbohydrates and fat that you prefer.
A good starting point for fat intake is 15-30% of your overall calories or between 0.6-1 gram per kg of your target bodyweight.
Carbohydrate intake will be determined by whatever is left over, however your activity will also contribute to how many will work for you. If you do exercise a lot, in particularly high intensity and or long duration endurance exercise you may need more carbohydrates. A good place to start is between 2 and 3g per kg of desired body weight.
See your carbohydrates and fat as dimmer switches where if you adjust one switch, you must counter that by adjusting the other. This ensures you stay within your calories.
Putting the Macro Split Together
For our 80kg person with a target body weight of 70kg, we know that they need 112-140g of protein per day (448-560 calories from protein. There is 4 calories per gram of protein).
This would give us the following macronutrient split:
Protein: 112-140g (448-560 calories)
If we assume they need 2200 calories per day to lose weight, that leaves us with 1640-1752 calories left for carbs and fat. You can decide how you will increase or decrease your fat and carbohydrates based on your preference.
Carbohydrates: 140 - 210g (560-840 calories)
Fat: 42-70g (378-630 calories)
As you can see, the amount of carbs and fat will vary depending on how many calories you need to lose weight.
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The next thing to look at is how many meals per day you should eat.
Meal frequency and weight loss
There is no perfect meal frequency for everyone and there is no perfect time to eat.
The graphic from a study comparing weight loss diets below highlights how whether you eat less frequently (left of the line) or more frequently (right of the line) there is very little difference in weight loss. So providing your calories (how much you eat) are matched it doesn’t really matter how often you eat.
Some people prefer to eat 3 meals per day, some prefer 5-6 smaller meals and some people do best with 2 larger meals. The best approach is to find what works for you and stick with it. My experience finds that a good starting point is to eat 3 main meals per day and 2 x high protein snacks.
Fruit, vegetables and fibre for weight loss
The next thing to look at are fruit, vegetables and fibre.
Fruit and vegetables are an important part of a healthy diet and they have many health benefits. They are also low in calories and can help you to feel full. Research has shown that high fibre intake can also promote weight loss and sticking to your diet when consuming a calorie-restricted diet.
The recommended daily intake of fruit and vegetables is 5-7 servings per day. A serving of fruit is 1 piece of fruit. A serving of vegetables is 1/2 cup of cooked or raw vegetables or 1 cup of leafy green vegetables.
Fibre is an important part of a healthy diet and can help you to feel full and stave off cravings. The recommended daily intake of fibre is 25-30 grams per day.
The best way to get your daily intake of fruit and vegetables is to eat a variety of different fruits and vegetables every day. This will help you to get the nutrients you need and it will also help you to stay on track with your weight loss goals.
Putting it all together
The best diet for fat loss is a diet that includes all of the major food groups in the right proportions. Eating a variety of different foods every day will help you to stay on track with your weight loss goals and it will also help you to get the nutrients you need.
Download your free sample fat loss meal plan using the link below.
I recommend starting the day with a balanced meal of protein, high fibre carbohydrates, a small amount of fat and some fruit or vegetables. One of the reasons I like to forward load my day with calories is that research shows that eating breakfast can increase calorie expenditure and help with fuelling exercise.
Breakfast: 2-3 eggs with spinach and spring onion and 2 x slices of wholemeal toast. Or 50g of oats, 1 x scoop of whey protein, 1/2 cup of berries and 150ml of milk of choice
Lunch will also be a balanced meal of protein, high fibre carbohydrates, a small amount of fat and some fruit or vegetables. Like breakfast, helps ensure you get all of the nutrients your body requires, provides you with enough energy and helps prevent you from over eating.
Lunch: Leftover chicken thighs, 1/4 cup of rice, mixed vegetables, lemon juice, olive oil and spices. Or just keep things simple with a wrap or sandwich!
Snacks during the day will typically be a portion of fruit/chopped vegetables/pickles with a portion of cheese or boiled eggs. Meat slices and low fat, high protein yoghurts (Skyr, Greek Yoghurt) are also good options. To help fuel later exercise sessions I might add a portion of carbohydrates like half a bagel or 3 x Ryvita crackers
Dinner will be a lean protein source, usually a slightly smaller amount of carbohydrates and plenty of vegetables
Dinner: Salmon stir fry (salmon, mixed stir fry veg pack, egg noodles, chilli, soy sauce and coriander) or chicken and sweet potato cubes with mixed vegetables.
Bedtime Snack - Before bed I recommend having another high protein snack like whey protein with 150-200g of Greek Yoghurt and 1/2 cup of mixed berries. This can help ensure you hit your protein targets for the day and help you feel satisfied in the evening. Another one of my favourites is having something like cottage cheese on toast with fruit as it helps me feel satisfies before you go to sleep.
Late night eating and fat loss
Despite popular beliefs than late night eating can lead to fat gain, the literature shows us that eating late at night will not contribute to fat gain and can actually promote recovery and muscle retention. Be mindful of high calorie foods late at night as these are easy to over eat and will likely lead to weight gain.
As you can see, this is a high protein, high fibre diet with a moderate amount of carbohydrates and fat, which is the perfect starting point for most people.
You can then adjust the macronutrients (carbs, fat, protein) and meal frequency to suit your individual needs and preferences.
You can also add in additional snacks if you find yourself getting hungry between meals. The most important thing is to find a diet that works for you and stick with it!
See how I can help?
For more help with your weight loss, check out our signature metabolic testing weight loss programme, Ignite. Ignite uses a combination of clinical tests and advanced technology to give us an understanding of not only how many calories your body needs each day, but also exactly what foods are going to be best for helping you achieve your goals. We then provide our clients with a customised diet plan that works with their bodies and helps them lose weight fast!