Diet Myth 3: One superfood will make you skinny

When it comes to diets for weight loss, we have been bombarded by a whole host of conflicting messages over the years. Is fat good or bad for you? What about carbohydrates? Is fruit good or is it too high in sugar? I believe this explains the rise of single food diets – their simplicity. In most cases, the idea is that you replace some or all of your meals with a single food. You have the grapefruit diet, the cabbage soup diet, the potato diet, the rice diet, the mushroom diet, and on and on. These diets are some of the most successful for short term weight loss but they are also the least healthy.

Single food diets are a classic case of taking a tiny bit of science and blowing it all out of proportion. For example, it is true that studies have shown a compound in grapefruit juice can help with weight loss and reduce inflammation. What they don’t tell you is that most of these studies have been done in mice and rats. You are not a rat being force fed a very high fat diet! What’s more, any increase in fat burning is modest, the equivalent of an extra 50kcal a day in a human. That’s the same amount found in a medium apple. 

Regardless of the superfood chosen, no one food can cause significant weight loss on it’s own. Any weight lost on these diets is due to eating fewer calories. By their nature, these diets are incredibly restrictive. Yes, if you replace a normal 500Kcal meal with 50 Kcal of grapefruit, you will lose weight! Most people on these diets end up eating less than half the calories they normally would. That is the definition of a crash diet! Even the diets which only replace one meal a day with the chosen superfood will dictate what you can eat for the rest of the day. And invariably there is no sugar, no alcohol and no junk food. In each case, it’s the cutting back on burgers that causes weight loss, not the magical fat burning properties of cabbage.

The other reason single food diets work is boredom. On the potato diet for example, you literally eat nothing but potatoes. You can have them any way you like (except as chips or crisps), but no other foods – no vegetables, no meat, no dairy, just potatoes. In theory, you can eat as much as you want. However, after a couple of days of potatoes for breakfast, lunch and dinner, you will get so tired of them you will invariably eat less. This is backed up by research, which has shown that most of us eat far more if we are presented with many different foods. In one study, when people were presented with a buffet with a wide range of foods they consumed, on average, 50% more calories than at a buffet with large portions but fewer foods.

Needless to say, these diets are very unhealthy long term. Usually the superfood chosen is a fruit, vegetable or starch (such as potatoes or rice). Such foods tend to be low in protein and fats, and offer a limited range of vitamins and minerals.  The lack of protein is of particular concern. Numerous studies have shown that consuming plenty of protein helps to preserve muscle mass when dieting. In other words, more protein makes sure it’s fat you are losing, not muscle. While you may lose loads of weight on these diets, it’s likely you are losing both water and muscle mass along with the fat. This in turn will slow down your metabolism, meaning you burn fewer calories at rest. Not ideal!

Single food diets are the very definition of unsustainable, both from a physical and mental point of view. The lack of variety raises the risk of serious vitamin and mineral deficiencies. At the same time, the very restrictive nature of these diets can encourage disordered eating behaviours. So yes, while slashing the calories will cause weight loss, single food diets are quite possibly the least healthy way to do it!

Diet Myth 2: One macronutrient is making you fat

Elimination diets have been some of the most popular for decades and new versions are emerging all the time. These are diets that claim one particular macronutrient (fat, protein or carbohydrate) is responsible for all your weight problems. By vastly reducing or eliminating these foods, you will easily lose weight. Over the years every macronutrient has been under fire – you have low fat diets, low protein vegan diets, and the most popular, low carbohydrate diets. Each will have their glowing testimonials and dramatic before and after photos. All of these diets will work for some people, some of the time.

There is also a grain of scientific truth in each case. For example, fat is the most calorific nutrient, with 9 Kcal per gram compared to the 4 Kcal per gram for protein or carbohydrates. So eating a lower fat diet will reduce your calorie intake, helping to create a calorie deficit. This encourages your body to burn it’s fat stores to make up the difference, leading to weight loss. However, like all macronutrients, fats are essential for life and eating too little fat can have a serious impact on your health. And some fats, such as those found in nuts and oily fish, protect against all kinds of diseases. There is also the question of what you replace the fat with. Fat carries flavour, so using very little can lead to bland, tasteless food. In the 80’s and 90’s when low fat diets were particularly popular, there were all kinds of low fat snack foods loaded with salt and sugar – not an improvement!

Veganism is one of the big health trends of 2019. And there are certainly proven health benefits to following a diet with less meat. Studies have shown that vegetarians have much lower rates of heart disease, high blood pressure, Type 2 diabetes, obesity and certain cancers. However, this is not necessarily the result of eliminating animal products. After all, crisps, chips, cola and chocolate are all vegetarian. Rather, those who follow a vegetarian diet tend to eat  more fruits, vegetables, nuts, seeds, beans and lentils. Such diets are lower in saturated fat, lower in overall calories and higher in fibre and phytonutrients (found in fruits and vegetables). Many people who lose weight on a vegetarian/vegan diet do so not because of the lower protein intake, but because they are getting more fibre (so feel fuller for longer) and can no longer have their usual junk food and take aways.

Low carb diets remain some of the most popular, whether that’s Atkins or the Ketogenic diet. Most low carb diets provide enough carbohydrates (usually from vegetables) to keep the brain happy, but not enough to fuel all our other activities (the ketogenic diet is an exception – see my previous post here). With all low carb, high fat diets, the idea is to force the body to burn fats rather than carbohydrates for energy.  And it is true that without access to carbohydrates the body will burn more fat. But this will only lead to weight loss if there is an energy deficit. If there are plenty of fats available from your last meal, there is no need to for your body to use it’s fat stores. What’s more, we get most of our fibre from healthy carbohydrates such as fruits, vegetables, and wholegrains. Following a low carb diet long term can actually increase your risk of certain diseases, such as bowel cancer.

So once again we are back to the truth about losing weight: You need to eat fewer calories than you use. Dramatically cutting back on any macronutrient will limit your food choices, especially of junks foods. For example, burgers contain simple carbohydrates from the bun , while the beef and cheese add plenty of fat and protein. Whether you go low carb, low fat, or vegan, standard burgers are off the menu. In each case, it’s the cutting back on burgers that causes weight loss, not the lack of carbohydrates (or fats, or protein).

In most cases, to safely lose weight and keep it off, you are better off going with a balanced approach. This means reducing unhealthy foods high in saturated fat and simple carbohydrates, and replacing them with healthy foods such as fruits, vegetables, nuts, wholegrains, pulses (beans and lentils), and fish.  Not nearly as simple or exciting, but much more sustainable!

Diet Myth 1: There is one diet that will work for everyone

“You have your way. I have my way. As for the right way, the correct way, and the only way, it does not exist.”


Despite the near constant hype about the latest fad diet, research has shown that fat loss remains a numbers game. ALL diets work by creating an energy deficit, whether that’s by cutting down on carbohydrates or fats or portion sizes. The only difference is in how easy or difficult a particular person finds it to stick to a particular diet. So it is no surprise research has revealed the best diet for weight loss: The one you stick to!

All diets will work for some people, some of the time. No one diet will work for everyone all of the time. It does not matter whether you are going vegan, low carb, low fat, paleo, ketogenic, or only eating at certain times of day. If a particular diet causes you to eat fewer high calorie foods, then you will lose weight. Despite claims of activating particular hormones or metabolic processes in the body, fat loss is fundamentally about eating fewer calories than you use.

What’s more, while the “rules” of every diet vary, the majority will:

  • Reduce or eliminate high sugar, high fat snack foods (chocolate bars, cookies, cake, etc.)
  • Reduce or eliminate take aways and junk foods (burgers, pizza, etc.)
  • Reduce or eliminate high sugar foods
  • Reduce or eliminate alcohol
  • Reduce highly processed food

All sensible suggestions you will find in every healthy eating plan. So, when choosing a diet plan, look for the one which looks easiest for YOU to stick to. Remember, sustainable weight loss is not about a quick fix but long term changes in the way you eat.

Tip 30: Fat loss is a long game

My final tip for you is also one of the hardest for people to accept: Diets don’t work.  Numerous studies have shown that over 95% of people who lost weight will have put all of it back on (and more) within 5 years. In order to keep the fat off over the long term, you have to make lifestyle changes that you can maintain forever.

Many people see diets as a temporary thing. They will eat a certain way for six or eight weeks, lose a stone, and go back to their “normal” diet. Problem is, their normal diet is what got them into this pickle in the first place! Within a year they’ve put all the weight back on and then some. In order to get the benefits of any healthy eating plan, you have to maintain it long term. In fact, studies have shown that people who yo-yo between a low body weight and a much higher one, are at more risk of certain diseases than those who remain overweight for years.

Successful long term fat loss is about finding a diet and exercise plan you can happily stick to. No one can give up all their favourite foods forever, so work in the occasional treat. But make planning healthy meals and cooking for yourself the new normal. Fundamentally, the keys to keeping the fat off are the same as losing it:

  • Get plenty of lean protein, especially fish and pulses
  • Increase vegetable intake
  • Switch to complex carbohydrates
  • Drink more water
  • Reduce take aways and junk foods
  • Reduce highly processed foods
  • Reduce or eliminate high sugar foods
  • Reduce or eliminate alcohol

Many people find that doing more exercise motivates them to eat better. Find a form of exercise that doesn’t feel like a chore, whether that’s joining a casual football team or taking up belly dancing. Don’t be afraid to try all kinds of sports and activities until you find the one that’s right for you. Over the years I’ve tried gymnastics, ultimate frisbee, weight lifting, distance running, rollerskiing, yoga and javelin throwing. We are all athletes, it’s just that some of us have yet to find our sport.

Ultimately, to lose the fat and keep it off you need to decide what you can live with and avoid the extremes. Sustainable fat loss is not about a quick fix but making changes that stick.

Tip 29: Mind your serving sizes

When it comes to fat loss, it’s not just what you eat that counts, but how much. In fact, reducing your serving sizes is one of the simplest ways to reduce your calorie intake and encourage fat loss. Despite the popularity of diets that claim you can eat however much you want so long as you avoid certain foods, how much you eat matters. No matter how healthy the food, too much will lead to weight gain.

Part of the problem is that many foods are sold in packages that look like they could be one serving, but which are really two or three. For example, a single steak in the supermarket might be 250-300g when a sensible portion is 100-125g. Likewise, many of us buy ready meals what are meant to serve two people, but eat the whole thing ourselves. What’s more, restaurants often serving very generous amounts of food (so you feel you got your money’s worth). The more often you eat out, the more warped your sense of what a normal serving size is.

There is also the issue that nutrition circles, the words portion and serving do not mean the same thing. A “portion” is a standard measurement of that food. However, a “serving” is usually defined as the amount you would expect to have in a single meal. For example, a portion of bread is one slice but a normal serving of bread is two slices. The government might say that you should be getting eight “portions” of carbohydrates a day, which sound like a lot. Until you realise that eight portions is a 60g bowl of cereal (3 portions), a sandwich with two slices of bread (2 portions) and a 240g serving of cooked pasta (3 portions).

To get your serving sizes under control, you need to get a sense of how much you are eating. The first thing to do is buy a decent set of digital kitchen scales and measuring cups. Then you need to start weighing up the foods you normally eat. This can be time consuming at first, but after a couple of days it becomes second nature to weigh things as you go. Once you know how much you are eating, you need to develop a sense of what a normal sized serving looks like.  For example, a standard serving of meat or chicken is 100-125g while a serving of raw or cooked vegetables or fruit is 80g. For high fat foods like cheese and nuts, a serving is only 30g.

You may find you are eating far more than the recommended amounts of meat or pasta, but that your servings of vegetables are not big enough. A good example is cereal. Pour your normal amount into a bowl and weigh it. Then check the box to see what a normal serving size is – in most cases, 30-40g. Most people find they are pouring far more than that. However, once they’ve weighed out a 40g portion a few times, they then learn how it looks in the bowl and no longer need to weigh it.

If you are going to lose the fat and keep it off, you need to learn what a sensible serving is!

Tip 28: Embrace the cold

When it comes to burning calories, most people assume that professional endurance athletes use the most energy. And it is true that a cyclist on the Tour de France can get through over 5000 kcal a day. However, this total can be rivalled by Olympic swimmers, with reports of Michael Phelps eating over 9000 kcal per day. The difference is that he did his workouts in cold water.

Over 60% of the calories you eat are used just to keep you alive, with less than 40% fuelling things like exercise and digestion. This is your base metabolism and is determined by a number of factors such as genetics, how much muscle you have, and whether you are fighting off a cold. So anything that raises your base metabolism can be a big help in fat loss. And one of the biggest factors influencing your metabolism is how hot or cold you are.

Fundamentally, it takes a lot more energy to keep your body at 37°C in the cold than in a warm room. This means you can boost your daily calorie burn simply by spending more time in the cold. What’s more, when you spend more time in the cold, your body converts dangerous white fat into active brown fat. While white fat just sits there (causing inflammation which can lead to heart disease and diabetes), brown fat burns energy to produce heat. The more energy you burn, the easier it is to create a calorie deficit and lose the fat. In fact, not only do lean people have less fat than obese people, they tend to have more brown fat than obese people.

So take advantage of the cool January weather to stoke your metabolism. Turn down the thermostat by a couple of degrees. Take a walk or run outside, rather than hitting the gym,  or try a swim in cold water. Just be careful not to warm up with too much starchy comfort food afterwards!

Tip 27: Broaden your food horizons

Check out my recipe for rainbow prawn stir fry

People often claim that “diet food” or “heathy food” is boring and tasteless. It is one of the reasons many people struggle to stick to a healthy eating plan. However, I believe that the problem is not that healthy foods are less flavourful than junk foods. Rather it’s their choice of foods which is the problem.

Too many people have an outdated idea of what low calorie food looks like. When they want to lose weight they switch from burgers and chips to salad with no dressing and rice cakes. They give up bread and pasta and instead stick to plain white fish with boiled vegetables. Of course these particular foods are very bland and boring! You have to be very motivated to eat like this. Even if they do manage to reach their weight loss goals, they then return to eating the unhealthy foods they used to, and the weight goes right back on.

In order to lose the fat and keep it off, you need to find some healthy, lower calorie foods that you actually enjoy. One way to do this is to explore more ethnic cuisines. Simply put, the traditional British diet isn’t that healthy. Look at foods like fish and chips, pork pies, or sausages and mash. The focus is on fatty and processed meats (think sausages) and white carbohydrates (like pastry and chips). If you do get lean meats such as fish or chicken, they are served battered or breaded (like fish fingers or chicken nuggets) and often deep fried. And aside from the odd portion of peas, there are very few vegetables.

On the other hand, traditional Italian, Mexican or Japanese food contains far more vegetables and of lean protein. Incorporating some new foods and flavours can really help you stick to a healthier diet. The caveat is, you need to do most of the cooking yourself. Once again, restaurants and food companies know how much we like the taste of fat and sugar, so add plenty. A homemade chicken stir fry with loads of vegetables over brown basmati rice is an excellent healthy meal choice. However, it bears little resemblance to most Chinese take away dishes.

So take the time to look up some new recipes. Learn how to make a basic stir fry or fajitas (with whole wheat tortillas of course). You may just discover a whole new love of food even as you lose the fat!

Tip 26: Use sugar strategically

Something I see a lot of in my practice is diets high in sugar. Even people who are eating healthily can end up with a diet high in total sugars, especially if they have a lot of processed foods. Unfortunately, regardless of where the sugar comes from, it has the same effect on the body. Unless you are an athlete who uses sugar strategically, too much sugar can make fat loss a whole lot harder.

Foods high in simple sugars are very easy to digest and enter the bloodstream quickly. In response to the increased sugars in the blood, the body releases insulin. Insulin tells cells to absorb the sugars from the blood and use or store them. With easy to digest simple sugars, you get a large spike in blood sugar very quickly after eating. This may make you feel good, but high blood sugar levels are dangerous, and can damage the eyes, nerves, kidneys and blood vessels, and even result in a diabetic coma. To prevent this, the body releases a large amount of insulin to bring your blood sugar level back to normal. The more insulin released, the faster the sugar is cleared from the blood, giving you that sugar crash.

The problem with too much sugar is it can lead to insulin resistance. Our lifestyles mean most of us get very little exercise, so don’t use up the stored glucose between meals. We then eat plenty of sugar so the pancreas has to make more and more insulin to force the already full cells to store more glucose. In type II diabetes, the cells have stopped reacting to insulin and are not absorbing the circulating sugars the way they should. If muscle cells don’t absorb the glucose it stays in the blood, causing high blood sugar levels.

What’s more, a diet high in sugar encourages weight gain. Normally, glucose is stored in the muscles and liver as glycogen and then released back into the bloodstream between meals. However, glucose is not our only source of energy; we use fats as well. In fact, free fatty acids are our primary source of energy at rest. Like glucose, high insulin levels after a meal ensure free fatty acids are stored in muscles and fat cells. Falling levels of insulin between meals then causes the release of stored glucose and the breakdown of fat into fatty acids that can be used for energy. However, if insulin levels are always high (either through constant snacking on sweet treats or type II diabetes), then there is never a strong signal to breakdown fat. This makes it very difficult to lose body fat and much easier to gain it.

If you are looking to cut down on body fat you need to reduce the amount of sugar in your diet. Try to keep cakes, biscuits, chocolate and ice cream as occasional treats. Switch from drinking squash or cola to water and mind the amount of sugar you put in tea and/or coffee. Also, be sure to check the sugar content of any sauces or condiments you use, as these can be loaded with sugar. Once again, the fewer processed foods you eat, the easier it is the reduce the sugar in your diet.

However, there are times when a little extra sugar can actually help fat loss: During and after exercise. If you are doing endurance exercise such as running or cycling for more than an hour, then a high sugar sports drink can help you go harder for longer. The longer and more intense the workout, the fitter you get and the more calories you burn. What’s more, after any exercise your body needs proteins and carbohydrates to repair muscles and refill depleted energy stores. The insulin spike caused by simple carbohydrates tell your cells to absorb not just the glucose, but more protein as well. A meal high in simple carbohydrates and protein immediately after a workout can help you recover much faster, so you can go hard again tomorrow.

Fundamentally, the more exercise you get, the more sugar you can get away with in your diet!

Tip 25: Mind the alcohol!

Britains love their alcohol. It has been part of the culture for a very long time, but it’s only relatively recently that we’ve started to realise just how damaging a daily drink or two can be. Among other things, the more you drink, the more likely you are to be overweight or obese1. So if your goal is to lose the fat, you really need to mind the amount of alcohol you’re drinking.

Alcohol can sabotage your fat loss goals in several ways. To start, alcohol itself is relatively high in calories, with 7 kcal per gram (as opposed to 4 kcal per gram for protein or carbs). A pint of 4% alcohol lager has about 180 calories, while a large 250mL glass of 13% red wine has about 225kcal. And we rarely stop at one! What’s more, the body does not process liquid calories in same way as solid ones. It takes a lot more fluid to feel full than solid food. I find I can easily have a couple of calorie laden cocktails, and still have room for a three course dinner (with wine!).

Of course, one of the effects of alcohol is that it lowers inhibitions and makes you feel more relaxed. This in turn can lead to poor food choices and overeating. Not because the alcohol makes you hungry, but because you are more likely to ignore logic and rules and act on impulse. You are far more likely to have dessert (or a larger dessert) after a couple of glasses of wine, simply because you fancy it and no longer care about the consequences.

Alcohol can also affect the quality of your sleep. As we’ve seen before, a lack of sleep can lead to overeating the next day. However, many people swear by a “nightcap” to help them sleep. And it is true that drinking alcohol helps you to fall asleep more quickly. The problem is alcohol reduces rapid eye movement (REM) sleep, the stage where we dream and which is the most restorative. Even if you get a full night’s sleep, disrupting REM sleep can leave you feeling tired, drowsy and unable to concentrate the next day. Alcohol also causes your whole body to relax, and not always in a good way. When the muscles of your throat get too relaxed, you get sleep apnoea and snoring. This reduces the quality of sleep and can cause you to wake up in the night.

Many people massively underestimate the number of units of alcohol they are drinking. The current government recommendations are for both men and women to have less than 14 units of alcohol a week, spread over several days. That’s six pints of 4% beer, six small (175mL) glasses of 13% wine or fourteen 25mL measures of spirits. Many of my clients tell me they don’t drink that much, and are shocked to discover that two large glasses of wine are half the recommended weekly units!

So the first step is to keep a drink diary to see how just much alcohol you drink per week. You can find drink tracker apps on the Drinkaware website. However much you drink, consider cutting back. Many people have found that cutting out alcohol completely for a month or so can really kick start their fat loss goals. On the other hand, if you truly enjoy your drink you are better off planning regular treats rather than banning it completely. Give yourself at least three alcohol free days a week, and stick to less than two small drinks (half pints of beer, small glasses of wine) when you do indulge. Rather than having an entire bottle of cheap wine, buy a better bottle and savour it over several days. Likewise, rather than having a cheap six pack of lager, have one or two bottles of something more expensive. Make drinking a special treat rather than something you do every day.

Remember, sustainable fat loss is all about your attitude!


1. Traversey, G. and Chaput,J.R. Alcohol Consumption and Obesity: An Update.  2015 Mar;4(1):122-30. doi: 10.1007/s13679-014-0129-4

Tip 24: Cut down on processed foods

Check out my recipe for purple porridge

One of the reasons for the current obesity epidemic is the amount of processed foods we eat. Processed foods are ones which have been prepared and packaged by a company. Generally speaking, processed foods have a long list of ingredients, while unprocessed foods only have one ingredient. In other words, unprocessed foods don’t have ingredients, they are ingredients!

The problem is food companies know what we like: Lots of fat, salt and sugar. Processed foods often contain far more fat, salt, and sugar than you would ever add if you made the dish yourself. It makes no difference whether it’s something simple like frozen French fries or complex like a multi-course Indian ready meal. Processed foods may also contain colourings, preservatives, artificial sweeteners or other additives. While these have all been tested and found safe for human consumption, we know very little about the long term consequences of eating them.

Fundamentally, most of us eat foods that our ancestors would not recognise. We would all do better if we ate things as nature intended. There is solid research showing a diet high in vegetables, wholegrains, pulses, nuts and seeds, fish and lean meats reduces the risk of many diseases, including obesity.

In practice, avoiding processed foods means ditching junk foods like chocolate bars, crisps, biscuits and so on. It also means doing more of your own cooking from scratch, rather than relying on ready meals or sauces in jars. When you cook from scratch you can control how much, and what types, of fat and sugar you add. Consider the simple example of switching from a typical breakfast cereal to porridge. Porridge oats are higher in protein and fibre than your typical cereal, keeping you full. Plus you can add flavour in the form of fresh, dried or frozen fruit  and get one of your five a day. Even if you add honey or maple syrup to sweeten your porridge, odds are you will add far less than the sugar companies add to cereal.

Cooking from scratch may be more difficult and time consuming, but when it comes to losing the fat, processed foods are not your friend!