How to deal with conflicting dietary advice
Why is there so much conflicting dietary advice?
The answer: Because diet is difficult to measure.
Without understanding something properly, it is very difficult to change it. This also applies to your own psychological causes of weight gain and eating issues. Without understanding something properly, it is much more difficult to ‘change’ the right thing, it is a bit like looking for a needle in a haystack.
Somethings are easy to measure. An example of this is weight as you step on the scales and get a reasonably accurate number. Diet is not like that. The less accurate the reporting of information in research studies, the less likely you are to find what is really going on. Diet is usually measured using a questionnaire or a food diary. If you have ever filled one of these, you will know how easy it is to forget what you have eaten. That is if you decide to be honest about what you ate. Most people are well aware of what they ‘should’ be eating and most people are a little economical with the truth when they fill these out. Also, people who have certain characteristics are known to be less honest with reporting their diet. For example, people who have a BMI in the overweight range are known to underestimate what they eat more than people who have a BMI of 20-25. All of this ‘fuzz’ means messy data. Messy data means it is very difficult to find any patterns linking diet to health. It is a bit like looking at something in thick fog.
Why you should be careful about reading diet news in the media.
Answer: Papers like interesting headlines, not robust (boring) scientific facts.
The messier something is, the harder it is to work out what is going on. If that wasn’t enough, the messier something is, the more likely it is that random results will appear by chance. These random results are a problematic statistical artefact. This means that many research studies looking at diet is likely to be fighting a losing battle before they start. The media get tired of being sent boring press releases from scientists so when something ‘unusual’ crops up, it tends to get in the papers. It is likely that some of these things are due to a statistical artefact. Nonetheless these unusual findings get in the paper and often conflict each other and adds to the level of public confusion about what is ‘healthy’. This is why it is important for researchers to repeat studies to find things again and again so that the influence of ‘chance’ can be ruled out. The papers don’t include the caveat that the original scientific papers do, usually a paper will say we found ‘x’ but it is probably due to chance and needs to be repeated, a newspaper, won’t bother with that bit.
What lifestyle advice should you follow?
Answer: You probably know this already, and it follows your common sense.
It is very difficult to tease out the real diet facts from the newsworthy headlines. I was a research scientist for many years, and we were constantly disappointed with the little new information we found. Here I will cover the few a few things that most diet scientists agree on about what is a healthy lifestyle.
Which diet is the best one for me?
Answer: It depends. It is one which:
- Eat lots of different types of vegetables: Scientific evidence shows that the more vegetables you eat, and the more variety of vegetables eat, the healthier you are. It is likely that 5 a day isn’t quite enough, but it is a great start. As fruit includes a lot of sugar, it is wise to try eat more vegetables than fruit, at least 3 portions of veg a day and 2 fruit.
- Limit or ideally avoid processed meat: Processed meat often contains chemicals like nitrates which may cause heart disease and some cancers. Nitrates are used to improve colour, flavour and preserve the meat. Processed meat also contains a lot of salt which is linked to high blood pressure and heart disease.
- Limit or ideally avoid ultra-processed foods: Have a look at the ingredients list of some processed foods. Do you know what they are? If you don’t know what an ingredient is, do you really want to eat it? Many snack foods are made by chemical companies. Then why do we put them in our bodies? Although foods on sale in the UK may have been tested as safe for short term consumption, the long-term effects are unknown for many food additives. Life is busy and sometimes most of us need to buy things ready-made. If so, look at the ingredients, do you recognise them? Try to make as healthy a choice as possible. The more toxins you put in your body, the more work your body needs to do to get rid of them.
- Eat enough fibre: Fibre is important for gut health and regular bowel movements. It is thought to prevent colon cancer and can also help lower cholesterol and blood sugar.
- Reduce sugar and artificial sweeteners: Both sugar-sweetened and artificially sweetened fizzy drinks are linked to higher rates of weight gain. Even fruit juice has been linked to a higher risk of diabetes.
- Aim to be active on most days: Physical activity is important for mental health, bone strength and can also help weight loss and maintenance. Most research show that for substantial weight loss, diet is most important but that being active helps and is vital for keeping the weight off. Adults are recommended to do at least 30 minutes a day of activity that makes you start to sweat and speed up your breathing (termed moderate-to-vigorous activity). This should include strengthening and flexibility activities as well as cardio. To help with weight loss and to keep weight off if you have lost it relatively recently, it helps to aim for nearer 60 minutes per day of moderate-to-vigorous activity.
- Drink enough water: Aiming for about 2 litres a day, spread out throughout the day. Drinking to much or too little can interfere with electrolyte imbalance and cause havoc with all sorts of body systems. Drinking enough helps ease water retention as it promotes urination. As urine removes a lot of toxins from our bodies, it is vital to drink enough.
- Get enough sleep: Most people need between 7 to 9 hours of sleep. It helps to have a consistent routine of going to bed at the same time and getting up at the same time which can improve sleep quality and reduce stress levels. Your body and mind can learn to expect a consistent sleep routine making it easier to both wake up and go to sleep.
- Monitor caffeine: Caffeine is a stimulant which can cause problems with sleep, especially if consumed in the afternoon and evening. Drinking more than 400mg a day (four homemade filter coffees) has been linked to anxiety and high blood pressure. Beware of coffee shops as a large filter coffee from a well-known Seattle based coffee company has over 400mg in one cup (that is more caffeine than 4 regular cups).
It sounds easy but for anyone who has struggled with food cravings and their weight, that can sound insurmountable, but it is possible.
Why don’t ‘diets’ work?
Answer: They don’t tackle your mindset which is the real reason for weight gain.
- Broadly follows the guidelines above.
- Allows you to keep to a healthy weight without feeling restricted.
- One which you enjoy.
Diets do not tackle the underlying causes of weight gain; these are usually psychological. For many people emotional eating and binge eating happen to try and block out other feelings. Often emotional eating and binge eating are ways of distracting ourselves from unwanted thoughts and feelings. Constant thoughts about food mean we don’t have space to engage with this inner discomfort. A diet does not deal with that. As soon as you stop following the diet, the same issues are likely to surface again.
Why are restrictive diets especially harmful?
Answer: Restriction leads to falling off the wagon or bingeing.
Restricting your energy intake can allow you to lose weight in the short term. I think of this restriction as a beachball that you are trying to push underwater. The more you restrict, the more air gets put inside your beachball. That beachball keeps getting bigger and gets harder to push under the surface. Eventually it may explode, then you might binge. Instead, you could learn to manage the feelings before the beachball explodes. You can also learn how to deflate your beachball and keep it at a manageable size. If your beachball is at a healthy size, then your body is more likely to be too and you are more likely to be in control of what you eat.
How to lose weight?
Answer: If you want to lose weight, you need to eat less energy than you use. Although sounds simple, for anyone who has every had an issue with their weight, it is anything but simple.
Do I struggle with my weight because of my genes?
Answer: Genes might make it slightly harder, but they don’t make it impossible.
Researchers keep finding find genes which make it slightly harder for some people to lose weight, but their influence is relatively small and can be counteracted with lifestyle. The exception to this is in an incredibly small number of rare cases where a genetic difference directly causes weight gain. You would likely already know if this was your situation.
What is the quickest way to lose weight?
Answer: Probably the ‘wrong’ one.
It takes time to lose weight sensibly without restriction. I know we all want everything yesterday. You need to find the ‘sweet spot’ of losing weight gradually and not feeling too restricted. That sweet spot is different for everyone. Retraining your mind during sensible weight loss and gradually reintroducing what you will eat when you have got to your goal weight is important to avoid putting the weight on again.