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Chewing the fat over low carb high fat

As part of our dietary challenge, a team of dietitians and nutritionists in the Heart Foundation have switched to a low carbohydrate high fat (LCHF) way of eating, to gain personal knowledge of the approach. How did they go? Are carbs out and fat back in?

Over the past 2-3 years, the health headlines have been saturated with reports that fat is back, the real dietary villain is carbohydrates/sugars, and the increasing popularity of a low(er) carbohydrate high(er) fat (LCHF) way of eating. So, with this in mind, it was time for our group of nutritionists and dietitians to look at adopting the principles of LCHF for a month and to share their personal experiences.

To recap, seven of our nutrition staff are trialling some of the hottest dietary trends for a limited period to explore the benefits, challenges and sustainability of following them. Ultimately, their goal is to gain personal insight into these different eating approaches. We found after a month’s trial of Paleo, that the approach had more in common with the Heart Foundation’s advice than many would probably expect. Will the same hold true for LCHF?

What is low carb high fat eating?

While there are many definitions of what is considered a LCHF diet, it essentially involves restricting carbohydrate intake, in favour of higher fat intakes. There can be great variation between what is /isn’t included, however, followers typically eat a whole food diet including non-starchy vegetables (such as broccoli, mushrooms, spinach and cauliflower) meat (including fatty and processed meats e.g. bacon, sausages) poultry, fish, eggs, nuts, seeds, full-fat dairy and natural fats (like avocado, butter and coconut oil/cream). Processed foods, sugar, refined carbohydrates and starchy foods (like bread, pasta, rice, and starchy vegetables such as potato, taro and kumara) are either avoided or heavily restricted, as are refined seed oils. Legumes may/may not be included in some versions of this diet and fruit is usually limited, depending on carbohydrate content.

Paleo vs LCHF

The Paleo approach that our dietitians and nutritionists followed in the first trial involved removing dairy, grains, potato, legumes and processed foods (with the exception of wine and coffee which were needed for sustainability and sanity).

The LCHF approach that we adopted followed a similar vein with a continual focus on non-starchy vegetables. However, it had the major difference of allowing dairy and some legumes (including peanuts) back in. While not typically included in a true LCHF dietary approach, our LCHF trial group decided that, rather than completely removing items such as wholegrain bread and other grain-based foods, they would limit these as a much as possible. In doing so, the end goal was a lower carbohydrate (approx. 50g – 100g) and higher fat intake over the course of a day

Personal experiences

Two of our seven nutritionists and dietitians who completed the Paleo trial didn’t take part in LCHF. One was training for the Auckland Marathon and was conditioned to a relatively high carbohydrate intake. She chose not to modify during the most intensive part of her training programme. Another was travelling overseas for a large part of the trial.


My eating pattern over the month tended to be lower carbohydrate (continuing the removal of potato, rice, pasta) and a slightly higher fat intake (largely coming through from nuts, seeds and olive oil). I liked the LCHF approach of limiting certain things rather than completely cutting them out and, therefore, the odd slice of Vogel’s crept back in on more active days or as a base for poached or scrambled eggs. I didn’t limit fruit throughout the month. Instead, I tried to vary the snacks by having things like celery with peanut butter, celery and cheese or nuts as low cost higher protein/ higher fat snacks. I found the approach fine in terms of cost, sustainability and satiety. In a nutshell, it ended up being a slightly more liberal version of Paleo – built around non-starchy vegetables in place of what was previously, rice, pasta, and starchy bases to meals.  Cauliflower rice continues to be a hit!


Similar to my adoption of Paleo, I chose to go ‘LCHF-ish’ during this dietary challenge. I continued to have oats for breakfast but then ensured that no other starchy or grain-based foods crept in during the remainder of the day. I had really missed dairy during our Paleo challenge, so it was great to be able to incorporate this back into my diet. However, after so many years of drinking trim milk I found that I couldn’t embrace full fat milk as it was much too creamy! Taste issues aside, I also chose not to increase my saturated fat intake from foods such as coconut oil, butter and fatty meat. Instead, I embraced foods higher in unsaturated fats such as oily fish, avocado, nuts, seeds and olive oil. While the LCHF approach permitted three ‘free’ meals per week, which could go some way towards helping followers not to feel so alienated when eating out, I don’t agree with referring to these days as occasions where followers “fall off the wagon” or make “mistakes”. I’m a firm believer that having a healthy relationship with food is just as important as healthy eating. For most of us, ALL foods can be part of a healthy diet. It’s just that we need to eat more of some and less of others.


As a bit of an experiment, I decided to go all in on the LCHF approach by trying to limit carbohydrates as much as possible and incorporating lots of different high fat options. I really appreciated adding back in dairy that I had avoided during my paleo month. The first couple of days were fine, however, by day three I was really struggling. I had low energy and mood, headaches, poor concentration and felt full and hungry at the same time. It all came to a bit of a head by day five when I "fell off the wagon" and ate a tortilla wrap for dinner. I was really surprised at how much better I felt within a short period of time. For the rest of the month, I reintroduced small amounts of starchy vegetables like kumara with my salads and the occasional piece of fruit. This was a lot more sustainable and limited any of the ill effects I experienced when my carb intake was really low. Overall, I found this regime a bit more expensive than my usual eating plan. Without the cheaper carb options and like the paleo pattern, I needed to be a lot more organised. My vegetable intake remained high through the month and it was a lot more manageable and realistic when I switched to lower carb instead of extremely low carb.


Moving onto the LCHF diet after Paleo was less of an ordeal than I thought it would be, if anything it gave me more freedom! It meant that I could have cheese and Greek yoghurt in my diet, but I did have to watch how many kumara I had at dinner time. I went a little too low in carbohydrate for the first few days, resulting in terrible headaches and a migraine. This made me reassess my diet and have a bit more carbohydrate at meal times. I was definitely low-er carb (compared to my usual intake) probably <100g/day but I still found the social part of eating very difficult. While my partner has been so supportive and joined me in these dietary challenges, I do think he’s hanging out for a big bowl of pasta or a few slices of Vogel’s! One of the biggest eye openers for me during this challenge was how much behaviour change and willpower was needed. And, as a dietitian it made me even more aware of the fact that if someone has been eating a certain way for pretty much their whole life, it’s a big ask to expect them to make a lot of dietary changes – and stick to it! PS – I’m SO over eggs and bacon!


Like Branko and Deb, I fully embraced the low-carbohydrate principles of this diet for the first few days. This led to me feeling light-headed and having a real lack of concentration at work. I decided to increase my intake of carbohydrates, mostly in the form of fruit and starchy vegetables – I can promise that no bread, cereals or crackers passed my lips for the whole LCHF period! I did struggle with what to put under my poached eggs and mashed avocado, but experimented with homemade seed crackers and the like, which mostly satisfied me. High-fat dairy wasn’t an issue for me – I love greek yoghurt and most cheeses – I just couldn’t manage full fat milk, especially in hot drinks. I’m a firm believer that children need regular intakes of carbohydrate to meet their energy needs, so I didn’t try this diet with my two children. They were interested in my ‘different’ meals though and even tried some of the alternatives like the seed crackers and cauliflower rice, with limited success. Definitely some positive outcomes from trialling this way of eating, but I’m not a fan of the high fat processed meats and high intakes of butter and fats which are promoted as being healthy.

Some of the meals we enjoyed on the LCHF challenge

So is fat back?

We found a similar finding to the Paleo trial that when a Lower Carb Higher Fat approach is built around mostly vegetables and cardio-protective fats, it has more in common with the Heart Foundation advice than different.

None of the group got on the coconut bandwagon and most opted to increase their fat intake through unsaturated sources such as olive oils, nut butter, nuts and seeds, avocado and oily fish, rather than through saturated fat. The exception was cheese and Greek yoghurt which were particularly popular, especially in the first two weeks after coming off Paleo.

The Heart Foundation’s advice is that with both fat and carbohydrate, quality rather than quantity is important. A range of intakes is acceptable but, with both, it is the quality and food sources that count. This is the cornerstone of the Heart Foundation’s nutrition advice and demonstrated in our visual food guide which includes healthy fats (with a focus on unsaturated fats, rather than saturated fats) in the ‘eat some’ category and denotes flexibility in terms of the contribution of fats relative to other food groups. Our advice also highlights the importance of non-starchy vegetables which are positioned in the ‘eat most’ category.

We would recommend that many people could benefit from some of the underlying principles of a lower carb higher fat approach such as: reducing refined carbohydrate foods like white rice, muffins, biscuits and pasta, increasing intakes of non-starchy vegetables and including some ‘healthy fats’. However, we do not recommend the elimination of any foods or food groups, unless there is a medically diagnosed reason to do so. Wholegrains, starchy vegetables, fruit and legumes (regardless of their carbohydrate content) can all be a part of a heart-healthy diet.  

We are sure the debate and headlines will continue to rage over carbohydrate and fats. While that happens, we need to remember that we eat foods, not one particular nutrient. If we focus on getting the overall foods right (mainly whole, less processed foods with plenty of non-starchy vegetables) then the nutrients will look after themselves.

(Disclaimer: The content in this blog does not represent the views of the Heart Foundation. Instead, it is the views and opinions of Heart Foundation staff who are speaking from personal experience.)

Find out our take on Paleo

Dave Monro, NZRD

Dave Monro, NZRD

Chief Advisor Food and Nutrition

I completed chef training while studying nutrition/ dietetics and enjoy combining both of these elements to develop practical solutions for families to eat healthier.