Gareths Keto Diet Experiment – Part 1: What is Keto and Why?!

Last Monday I started a Ketogenic (Keto) diet and will be doing so over a 6 week period. I will be blogging all about it here, every week.

Lot’s of people have been asking me ‘What the hell is Keto’ and when I explain it, ‘Why the hell would you want to do that?!’

Ha, well firstly without going into too much detail let me explain what Keto is:

What is a Keto Diet?

To put it simply, a Ketogenic (Keto) Diet consists of high amounts of fat, moderate protein and very low carbohydrates. So basically the main proportion of food on my plate will consist of fat, some protein, and a minimal amount of carbs. Sugar and starchy carbs are out – in are healthy fats, protein and vegetables.

When the body is only getting few carbohydrates, the liver begins to release ‘Ketones’ into the blood stream. These ‘Ketones’ are then used by the body to convert fat into energy, at which point the body is said to enter ‘Ketosis’ and becomes a fat burning machine basically. Fat’s are shown to be the most effective source of fuel to the body.

All those foods that I once thought were ‘bad’ and should be limited are back on my radar ūüėÄ Think bacon, eggs, cheddar cheese, soft full fat cheese, sour cream, full cream, avocado’s, coconut oils, butter, nuts & Nut Butters, thick juicy steaks and more!

For most people who eat a larger proportion of carbs the body never enters Ketosis –¬†instead, insulin is released by the body and the ingested carbohydrates are converted to glucose for energy. Thus glucose becomes the main source of energy for the body. Overeating of carbs can result in insulin resistance and often Type II Diabetes. Also, excess glucose is stored as fat which builds up, often causing obesity.

But doesn’t eating fat make us fat? NO!

The biggest misconception that people have when it comes to eating fat, is that eating fat makes us fat, particularly saturated fat. It all goes back to a study by Minnesota University Researcher ¬†Ancel Keys back in the 1950’s. Mr Keys travelled with his wife to seven different countries and collected blood samples from some of the population in each of those countries.

In short, his ‘Seven Countries’ study appeared to show that the risk of heart attack and stroke in those countries increased when the amount of fat consumed was increased.

The problem with this study is that it conveniently missed out countries such as Holland & Norway, where fat consumption, was high yet heart disease was low. He also missed out countries such as Chile where heart disease is high yet they don’t eat much fat. He actually had reliable data from 22 countries but only chose to publish those from 7, hmmm.

Big Fat Lies

The ‘Big Fat Lies’ video taken from documentary ‘Fat Head’, gives a quick¬†summary of the bogus science surrounding the theory that fat/cholesterol causes heart disease.

Keys filtered out any results that didn’t fit his high fat = heart disease hypothesis and included those that did.

Ian Leslie of The Guardian published an article ‘The Sugar Conspiracy‘ where he discusses Keys research and the criticism it has faced. ¬†He mentions how President of the US at the time Dwight Eisenhower suffered a heart attack in 1955 and insisted on making it public. Leslie writes “His Physician Dr Paul Dudley White, gave a press conference at which he instructed Americans on how to avoid heart disease: stop smoking, and cut down on fat and cholesterol”.

This advice began to take hold with doctors and the general public and still remains to this day. By the way, following Keys advice, Eisenhower cut out all saturated fats & cholesterol from his diet. He went on to die of heart disease in 1969.

Sugar & Insulin Resistance = Not good!

The theory that sugar/carbohydrates are doing the damage rather than fat is now gaining momentum. Gary Taubes, a US Physician and Science Writer has written several excellent books on the subject: ‘Why We Get Fat‘, ‘The Case Against Sugar, ‘Good Calories, Bad Calories’.¬†

For years now I’ve experimented with clean eating, – high protein low carb meals with next to no taste

Consuming sugar/carbohydrates raises insulin. Insulin, a hormone produced by the pancreas drives glucose into our blood cells to be transported to the liver/fat and muscles for energy. Excess glucose is stored as fat. The body cannot make use of this fat if it is configured to get its fat from glucose, therefore the stored fat simply builds until it clogs the arteries and increases the risk of heart attack, stroke and obesity.

Carbs Are Killing You Infographic

Infographic By Column Five Media

Over time as our consumption of carbohydrates increases so does the production of insulin. The body cannot cope with such high levels of insulin and the cells begin to become resistant. The result is often the onset of type II diabetes.

This excellent infographic from explains the effect of consuming too many carbohydrates nicely.

So Why Am I Doing Keto? What Are the Benefits?

Well, when you look at some of the benefits that the Ketogenic diet offers, it’s a no-brainer for me:

1. Lower Bodyfat/Water Retention = Leaner Body!

I’ve noticed over the years that I’m constantly feeling bloated. I exercise a fair bit, sometimes 5 days a week and have always eaten clean (ish!). Yet my body feels ‘soft’ to me.

Having experimented on/off with low carb diets, I notice this bloating feeling reduces. So I’m pretty sure it’s the carbs having this effect. I also did a DNA test a few years ago with DNAFit – the results showed that I was likely extra sensitive to carbohydrates, as many people are! Glucose and the resultant insulin spike is renowned for retaining water – in theory, a Keto diet should reduce this effect.

Also when the body becomes Keto-adapted it will turn to its stored fat stores for energy thus resulting in a lower body fat percentage.

2. Improved Mental Focus

Ketones are a preferred source of fuel for the brain. This explains why many people report a big increase in mental performance on Keto. My day job as a web developer and my evening job as an outdoor instructor requires constant focus. With the lack of sleep, I’m getting at the moment (due to two small non-sleeping boys :D), any improvement in mental focus is welcome!

Many type II diabetics become non-diabetic after doing Keto.

3. Increased Energy – Particularly for Endurance!

I love running and I love Obstacle Racing. Many of the events that I enter require endurance and often a constant supply of glucose/carbs. The problem is our bodies can only store a limited amount of glucose, on average 1600 calories dependent on muscle mass. Compare this to fat stores, our bodies can store 60-100,000 calories of fat!

Once glycogen/glucose stores are depleted, that’s when people during marathons etc. tend to ‘hit the wall’! However, when in Ketosis this does not happen since the body can then tap into its massive supply of fat for fuel. It’s also a more efficient fuel source for the body so in theory, once adapted my performance should improve.

4. Reduced Hunger – More satiating food!

Fat is twice as calorific as carbohydrate. 9 calories per gram vs 4 calories per gram. It’s also a preferred source of energy for the body, so we don’t crave it as much as we do carbs. We feel fuller for longer and don’t have to eat as often. For, me this is a big benefit. I’ve got a very busy lifestyle with a day job as a web developer, instructing and running OBSTAFIT. Looking after 2 boys and also exercising myself! So I struggle sometimes to get all the meals in that I should be eating!

5. Improved Cholesterol/Blood Pressure

Without going into the science too much, the Keto diet has shown to improve levels of HDL cholesterol (good cholesterol!) and to decrease levels of LDL cholesterol (bad cholesterol). The result is less build up in the arteries, therefore less risk of heart attacks/stroke etc.

Blood pressure is often reduced, also as a result of weight loss and lower insulin levels. High blood pressure is often a key factor in the cause of diabetes. Many type II diabetics become non-diabetic after doing Keto.

The Experiment

I’m treating this as an experiment for now. I’ve given myself 6 weeks to give it a go and to see whether this is something that may benefit me on a long term basis


I want to keep my current training plan as consistent as possible so as to not skew results. A typical week includes two functional full body strength sessions a week in the gym and 2 ¬†or 3 runs per week. I’ll be monitoring each of my workouts closely to see if I experience any positive/negative effects of the diet. The plan is to attempt to increase strength in my strength workouts. ¬†I¬†also hope to continue to make progress on speed/distance in my running sessions.

Links to my strength workouts below:

Full Body Strength Workout A

Full Body Strength Workout B



I’m looking forward to eating tasty high fat food! For years now I’ve experimented with clean eating, – high protein low carb meals with next to no taste. Keto meals are very tasty! All those foods that I once thought were ‘bad’ and should be limited are back on my radar ūüėÄ Think bacon, eggs, cheddar cheese, soft full fat cheese, sour cream, full cream, avocado’s, coconut oils, butter, nuts & nut Butters, thick juicy steaks and more!


On a Keto diet, carbs will be set low, ideally around 5% of daily calories. Fat should be the highest percentage with a moderate amount of protein. I’ve set my macro’s (macronutrients) at 5%/30%/60%(carbs/protein/fat). My BMR (Basal Metabolic Rate) calories are approx 1819 calories. Factoring in my exercise each week I’ve set my daily calories to 2367. So given the percentages, those calories will consist of:

Carbohydrates: 30g (120 cals)

Carbs Breakdown Keto

Protein: 177g  (710 cals)

Fat: 171g (1537 cals)

I will be keeping a diary each day in MyFitnessPal. I’m also sending over some of this data to our dietician Anna O’Neil who is going to check my nutrient/vitamin intake. Potassium and magnesium levels can drop sufficiently on Keto (due to loss of water/electrolytes); I need to make sure I’m getting plenty of these in my diet. Lots of dark leafy greens and bone broth!

Medical Tests

  • Blood Tests: A blood test will take place before and after the experiment. Checking things like HDL/LDL cholesterol levels and liver/kidney function
  • Blood Pressure: Will be checked before and after the experiment
  • Bodyfat %: Will be checked before and after the experiment

Weekly Monitoring

  • Weigh-ins: Every Monday morning I’ll weigh myself before breakfast
  • Pics: I plan to take photo’s from the front/side and rear every Monday morning
  • Ketone Levels: I will check the levels of Ketones in my bloodstream each day using Keto-Diastix from Amazon
  • Blogging: I will be blogging every week (possibly more) about my experience on Keto.

My Week 1 Update post is up, have a read of ‘Keto Diet Experiment, Week 1

Written By: Gareth

I'm a full qualified PT with a number of OCR's on my CV including the legendary winter Tough Guy. Also a former Light Heavyweight Kickboxing Champion and Black Belt! You'll usually find me over Roath Rec beasting training the guys to help them overcome their obstacles :D


2 responses to “Gareths Keto Diet Experiment – Part 1: What is Keto and Why?!”

    • Thanks Lynne. I’m 2 weeks in now and feeling great! Hoping to have the week 1 update written up today or tomorrow

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