Diet and body composition: 11 key take home points

The International Society of Sports Nutrition just released a position stand that reviewed the literature available regarding diet and body composition. You can read it here.  For those who want it broken down into more simple terms, I’ve distilled it somewhat into 11 key take home points. While much of this draws on literature from strength and power athletes, it is definitely applicable to the general audience too, given that resistance-based training is one of the best things you can do to support your health and body composition goals.

  1. There is a vast multitude of diets and within these, several subtypes of diet. Low fat, low carb, higher protein, Mediterranean, low calorie… and these will all work work to reduce body fat given the right conditions. As a practitioner, we need to be familiar of the evidence supporting each diet type to make informed recommendations to the people we interact with, both at an individual and population level. As someone who is interested in losing body fat, know that no ONE diet is going to suit everyone, and if you’re trying to follow something because your mate is too, but you’re not seeing the results, then potentially it’s not the right plan for you. Seems simple when I write it down – but I think important to remind you.
  2. All body composition assessment methods have strengths and limitations. It’s good to bear in mind the limitations of using just scales as the only indicator, as this doesn’t account for fat mass loss. I’ve had numerous clients basically freak out that they have gained a kilogram overnight because they’ve eaten something high in carbs (causing your body to hold water) or they have done a hard training session (inflamed tissue). It is impossible to gain kilo of fat over a week, let alone a night, but the obsession with scales can make even the most rational person a little … less rational. Thus, if you use the scales, then think about how this makes you feel. And do it at the same time each week, on waking, after you go to the bathroom – etc. IE try to make it consistent. Ditto re: skinfolds – choose a practitioner who is skilled and stick to the same person so any errors are at least consistent errors.
  3. While it’s not about ‘calories in, calories out’, as that is far too simplistic, we do need to create a deficit in calories to drop body fat. Don’t freak out by the next bit of (evidence-backed, science-informed) information: The more fat you’ve got stored, the quicker you can lose this body fat without losing too much muscle mass by creating a large calorie deficit. The leaner an individual is, it is better if the caloric deficit isn’t as dramatic, to help preserve muscle mass. We can use calorie cycling to do this (ie higher calories for some days, lower for others across the course of 7-14 days, such as the 5:2 approach), or a consistently lower calorie approach, whatever fits in with the individual and their adherence. This study found that working on a weekly reduction of 0.7% of body weight better than 1.4% for preservation of lean muscle tissue.
  4. A wide range of dietary approaches (low-fat to low-carbohydrate/ketogenic, and all points between) can be similarly effective for improving body composition, and this allows flexibility with programme design, which is great – again, there is no one right approach for everyone. AND there is no one approach that will suit the same individual all the time – context, physical activity, stress, budget etc will all affect the suitability of an eating style that will improve body composition. This in part could explain why Weight Watchers, which helped you drop weight in the past, is not working now – regardless of how many points you are under at the end of the day/week. Being flexible rather than dogmatic will go a long way to finding a plan that suits you. I will also add, however, that something based on minimally processed food contains more nutrients – this will nourish your body and provide nutrients to ensure metabolism, brain and gut health are optimised while shifting excess body fat.
  5. When protein amounts are matched in the diet, there doesn’t appear to be an approach that reports a meaningful reduction of fat when we look at different macronutrient composition. All are as effective as each other – it’s sustainability which is the factor to consider. If an individual is insulin sensitive, research shows they are going to be able to lose weight on a moderate carbohydrate diet and potentially perform better on that than a lower carbohydrate diet. The reverse is also true. In addition, when adding resistance training to the mix, in some instances insulin sensitivity is improved. Therefore, knowing your metabolic health markers initially can help you determine what dietary approach might work for you.
  6. However, a ketogenic diet has been shown to have appetite-suppressing potential in part due to its effects on our appetite hormones (as explained in this review), resulting in a spontaneous caloric restriction. That said, for some this may only happen initially and clinically I have seen that this affect appears to wear off. (Note, this is my clinical observation).
  7. Increasing dietary protein to levels significantly beyond current recommendations for athletic populations (up to 2g/kg body weight) may improve body composition as in line with the ISSN’s position stand. It is also much more satiating for those of us who aren’t athletes, particularly in a restricted calorie state (as I’ve discussed here). There is also evidence that increasing protein in the diet beyond 3g/kg body weight and creating a calorie surplus can increase muscle mass and decrease fat mass simultaneously- I know! It’s like magic! Except very difficult to eat that much protein for a lot of people.
  8. Time-restricted feeding (which I’ve written about here) combined with resistance training is an emerging area of research that has thus far shown mixed results with respect to body composition (ie see here and here, however eating within that restricted window does allow for improvements in metabolic health. Much like cycling calories, the window of time that people choose to eat should be based on individual preference in a way that is easy to be sustained in everyday life. There is more to gain from having a good resistance-based training programme and adequate protein (in the context of an awesome diet) than worrying if your eating window is 8 hours a day or 9 hours a day.
  9. Do we starve our metabolism, thus slow it down and lead to fat gain if we restrict calories too much? Only in the context of a restrictive caloric diet and in the absence of resistance training where muscle mass has reduced, and energy expenditure has reduced. This can be mitigated when these are accounted for (see here and here).
  10. In addition to this, clinically what seems to work well is having a metabolic reset meal, where more fat/carb calories are consumed (which some might call a ‘treat’ or ‘cheat’ meal, particularly in the fitness industry) – this might be 1-2 meals every 7-14 days depending on the individual and their goals.
  11. There needs to be more research on women, older adults
  12. There needs to be more research on meal frequency and timing combined with different caloric loads, and with different training regimes.

Despite all of the above, a member of my online nutrition coaching system shared with me her experience with improving overall health (and metabolic markers – prior to embarking on her regime her HbA1c was in ‘pre-diabetic’ range). She found focusing on a higher fat approach, coupled with water fasting helps her control her insulin resistance and overall health much more than focusing on protein intake. While a few years ago this would have set alarm bells ringing in my head, the longer I’m in the game the more I understand that it is so individual as to how someone will respond to a dietary approach. Being willing to experiment with different protocols will help you figure out what works best for you regardless of the research papers.

 

No willpower when it comes to food? Read this.

‘ The chocolate bar calls my name. No, really – I can’t NOT eat it if it’s in the house.’

Many people I talk to lament that they can’t control themselves when it comes to sugar or junk food – that they don’t have the willpower to say ‘no’ despite their best efforts. This implies that they have all the control. Now I’m not saying there isn’t an element of discipline that may initially be required when changing the way you eat, especially for people who have lost touch with their appetite and satiety signals which can happen when the food eaten drives unfavourable hormone responses in the body; a phenomenon which is common in the current food environment. However, there are other more powerful forces at play here. Your No physiology has far more say in your food decisions than you think, and I’m going to cover one of the main ones I see (and one of the easiest ones to correct) that will help people control their food intake, rather than let their food control them: the blood sugar rollercoaster

This is one of the biggest drivers of cravings in my experience. The type of diet that many people follow is either carbohydrate heavy or devoid of protein and fat. Both situations are going to set your blood sugar up for rise and fall of (what can be) epic proportions. When carbohydrate is broken down into the bloodstream into glucose, this takes our blood glucose level out of homeostasis (normal). One thing our body likes is homeostasis – a blood sugar level too high or too low will send signals to the brain that this needs to be corrected. The greater the fluctuation, the louder this signal is. Insulin is the hormone responsible for removing glucose from the bloodstream to be used immediately for energy or to store it for later use (in our muscles and liver) and return the blood glucose level to homeostasis (normal). However, a meal that has a large amount of carbohydrate (a high carbohydrate load) will accelerate this process, as will a meal that has minimal protein or fat (even with a lower carbohydrate load, as the proportion of carbohydrate will still be greater). This is because insulin responds first and foremost to carbohydrate, with a minimal response to protein containing foods, and (for most people) a negligible response to foods predominantly containing fat. When this process is accelerated, insulin moves too much glucose into cells and our blood glucose level rapidly drops to below normal (an over-correction). The signal to our brain therefore becomes a panic signal: blood sugar has dipped below normal and needs to be rapidly restored – enter sweet food cravings as our brain recognises these foods are going to return our blood glucose levels back to within that normal range much quicker than, say, a salad. Along with the cravings, we may experience ravenous hunger (where 15 minutes earlier you felt fine), irritability (‘hangry’) and (in particularly bad cases) dizziness, light-headedness, sweating and vision loss.

The quicker the carbohydrates are digested (especially in the absence of fat and /or protein), the higher the rise and fall in blood sugar, and the greater the effects on energy and subsequent cravings for food (and ‘lack of willpower’). You may be fine for the morning and rapidly cave in post 3pm. Or it might be that Monday and Tuesday you are sweet, but by Wednesday you are raiding the kids ‘treat’ box in the pantry.

This isn’t just an issue with regards to blood sugar management and fat loss goals, but more importantly it can make you feel pretty rubbish. So many people start a tirade of negative talk that they weren’t able to say ‘no’ to a paleo muffin or chocolate biscuit, that they have ‘failed again’ and they ‘may as well finish the entire packet as it’s the last time they’ll eat X food again.’ Or their inability to resist a sweet treat clearly indicates they aren’t worthy of whatever health goal or life goal they’ve set themselves, and will eat junk food as a form of punishment (or undereat to try to get it under control), and so starts the rollercoaster ride of the blood sugar crash.

While I’d like to say it’s really easy to figure out which foods are most likely to cause this process, recent research tells us that there is wide individual variation. You are your own best investigator when trying to figure this out. It is useful, of course, to know where carbohydrate comes form in the diet and starting to explore how these foods affect you specifically. You can use an app like Easy Diet Diary, My Net Diary, Fat Secret to help you determine where the carbohydrate is in your usual diet if all of this is new to you. That said, an energy dense, carbohydrate source is more likely to trigger a blood sugar response. These include (but are not limited to):

  • Dates
  • Other dried fruit
  • Honey
  • Rice malt syrup
  • Bread
  • Pasta
  • Rice
  • Cereal (including Nutrigrain, Cheerios, most cereals with a Health Star Rating)
  • Honey
  • Coconut sugar
  • Kumara
  • Potato
  • Grapes
  • Fruit juice
  • Vegetable juice with a fruit juice base
  • Vegetable juice with beetroot/carrot base

This doesn’t mean that all of the above choices are bad! At all, however, in the wrong amounts, and when eaten in isolation of other food choices, these are more likely to spike your insulin levels than other foods. Artificial sweeteners do not get a free pass either, unfortunately, with some showing the same physiological effects as sweet foods, eliciting a glucose/insulin response.

So… it’s not willpower, people – it’s physiology.

The easiest and *best* way that helps mitigate this is NOT a supplement. While these can be useful in certain situations or medical conditions, for most people it comes down to food timing and balancing. Protein and fat don’t have the same insulin effect, so they are not going to cause the same blood glucose rollercoaster that carbohydrate does. Incorporating these as the majority of your energy source is going to slow down the digestion of the carbohydrate you eat and the subsequent rise in blood glucose. Without reaching the same ‘highs’, your blood glucose doesn’t have the same drops – and cravings, hunger and crashing energy levels are FAR less likely. Fibre from non-starchy vegetables are another way to have this effect and help maintain a homeostatic state.

Despite what I say, what other experts tell you or what the literature or dietary guidelines tell us, you are your own best investigator when it comes to figuring out what works for you. One of the easiest ways to measure how food affects your blood sugar control is to assess the qualitative signs after eating: do you feel like falling asleep after a carb-based meal? Do you get moody, irritable, ‘hangry’ a couple of hours after eating? Are you fine, fine, fine, STARVING a few hours after eating? These are all good indicators that your blood sugar is in control of your actions (rather than you). From a quantitative perspective, getting a glucometer (finger-prick blood glucose reader) from the pharmacy and testing your blood sugar two hours after eating a particular food or meal is another good way to see how this affects your blood sugar levels. If it lurks above the 7 mmol/L mark at this point, then potentially the carbohdyrate type (or the context with which you ate it) isn’t ideal for you. Remember, this isn’t just about the food you’re eating at that time, it has implications for your food decisions later in the day. This is potentially more important if you find you have ‘no willpower.’ If you need help figuring out what to do from here, contact me for a consultation, we can sort it out.

Finally, pro-tip: when eating a meal, eat the protein and vegetables before tucking into the carbohydrate component. This will lower the post-prandial glucose response and the overall effect on your energy levels, levelling them out as opposed to leading to a crash.