Popular diets analysed and weight-loss myths exposed: fewer calories won’t work; more exercise won’t work; fat is better than sugar; sugar is better than processed carbs!  And why Presidents Eisenhower and Nixon are partly to blame

President Eisenhower’s heart attack in 1955 was a significant milestone in dietary thinking.  Cholesterol plaques in the blood vessels were taken as evidence that dietary fat was the culprit of heart disease.  Therefore, the American Heart Association (AHA) advised a low-fat diet to reduce fat intake to less than 30% of the total calories, with saturated fat to less than 10%.  Foods like meat, cheese, butter and eggs were excluded, and the gap was filled by carbohydrates.

This diet was tolerated with no significant adverse effect in the 50s and 60s because the gap was filled with real food – complex carbohydrates such as whole grains, beans, fruits, and vegetables.

The problems started in the early 70s.  President Richard Nixon backed a major increase in food processing, centred on cheap sugar and vegetable oil from corn.  Corn oil, and especially high fructose corn syrup (HFCS), moved food production from the farm to the factory.  It started the revolution that would see 90% of the food in grocery stores being processed and delivered in boxes and tins.

The availability of processed (addictive) food has changed dietary habits.  Instead of three meals a day, cheap snacks meant the average person also ate up to three of these.  The total calorie intake per person in the US has risen by 1,000% since the 1970s, resulting in a dramatic escalation in obesity rates – from 15% in 1970 to 39.5% in 2021!

Conventional weight loss advice – eat less and exercise more – missed the original problem.  And shifted our focus to calorie counting, ignoring that calories are not created equal.  The food’s quality, not the quantity of the food, matters.

Many argue that the pace of modern life forces them to depend on processed food because they don’t need to cook it, and processed or “fast” foods are generally tasty, cheap and convenient.

This blog will discuss why a low-fat diet failed to curb the metabolic disease pandemic, review how sugar and processed carbs damage your metabolism and outline the ultimate metabolic diet prescription.

Nutrition is the key to weight loss.  And weight loss is the key to reversing metabolic diseases.  We need to focus on the dietary pattern, not individual nutrients, to find a practical, sustainable and effective program.

Cutting calories simply slows down your metabolism and makes it harder to lose weight.  And exercising more is not going to work if you eat energy-dense, processed food.  Studies confirm that high fat in your diet speeds up your metabolism, helping weight loss and reversing disease, while high sugar intake increases insulin, the fat storage hormone.

There is no evidence that dietary fat causes heart disease. A ground-breaking study confirmed that most heart attack patients had normal cholesterol.  Another showed that a low-fat diet encouraged a high carb intake, converting a normal lipid profile into a heart attack and stroke.  Heart disease remains the number one killer despite a low-fat diet and cholesterol-lowering pills (statins).

However, a body of research argues that a diet high in sugar and processed carbs is the culprit for obesity and the metabolic disease pandemic.

Other studies have confirmed the prevalence of metabolic syndrome among people who consume sugar, processed carbs, animal protein and fast food, but low among those who consume fruits, vegetables, legumes, nuts, and seeds and who eat their dinner well before bedtime.

Your body weight “set point”

Your ideal weight is when you were 20, reflecting a good energy balance, eating enough real food to meet your energy demands.  In other words, your appetite and digestive system were set to a winning formula, giving you vitality but preventing disease.

Processed food, also known as calorie-dense food, contains many calories compared with real whole food.  It also stimulates your appetite to eat more.  Eating more wrong food results in too much energy stored as fat.

Your body’s “set point” represents the right food formula that matches your expected daily physical activity.  But the good news is that you can normalise your weight by returning to real whole food if you have a weight problem.

This was proven by chance when the US imposed sanctions against Cuba in 1990, reducing their processed food imports.  The Cubans had to depend on locally produced real food, and there was an average weight loss of 5.5%, and the death rate due to diabetes, heart disease, and cancer plummeted to its lowest levels!

Processed carbs worse than sugar

Table sugar (sucrose) contains equal amounts of glucose and fructose.  Glucose raises your blood sugar, while fructose, processed differently, does not.  Processed carbs raise your blood sugar more than table sugar as it is fully digested into glucose.  Eating pasta, for example, gives you double the blood sugar response of an equal amount of table sugar.

Excess fat from sugar and processed carbs is stored around the abdominal organs, which increases your disease risk compared with healthy fat storage under your skin.

You also consume more energy: two chocolate bars contain the same calories as six apples, but you could eat two chocolate bars at one time but probably not six apples!  Consuming processed food stimulates your appetite to eat more.

Your daily carbohydrate requirement is 75-125 gm.  Western diet provides over 300.

Plant-based diet is great but incomplete

Therefore, it is sensible to move to real food that contains fibre (which slows down sugar and fat absorption) and nutrients (needed to convert food into energy) rather than processed food stored as abdominal fat, causing disease.

A plant-based diet is a good option.  One study confirmed that it lowered BMI, total cholesterol, triglyceride, LDL (bad guy) and blood sugar compared with omnivores.  Plant-based eaters have a lower risk of metabolic disease and cancer, but nutritional deficiencies in protein, B12, iron, omega 3 and iodine.

However, a study has concluded that a plant-based or vegan diet can prevent or reverse metabolic disease, with a good nutritional cover of possible deficiencies.

Dr Dean Ornish investigated a low-fat diet as part of a whole plant-based diet.  The research was inconclusive, as other interventions with a positive impact, like stopping smoking, exercise and stress reduction, were included.  The plant-based whole foods probably masked the negative effect of the low-fat diet.

Another study reported that a low-carb diet is more effective than a low-fat diet in healthy women’s short-term (six-month) weight loss and is not associated with any adverse effect on cardiovascular health markers.

Elsewhere, fresh vegetable juice helped patients stick to the DASH (Dietary Approaches to Stop Hypertension) vegetable recommendation and was effective in helping weight loss in individuals with metabolic syndrome.

A low-fat diet causes weight gain, increasing triglycerides and lowering your HDL (the good guy cholesterol.)

Eat more fat and lose weight

Unlike sugar, fat has a neutral insulin effect, making you look good and feel great.  Your body burns more fat, loses weight, and you enjoy steady energy all day.

Healthy fat in avocados, nuts and seeds is high in fibre, makes you regular and feeds the microbiome to produce butyrate, a prominent marker of gut health.  Fibre also helps you achieve your ideal body weight and prevent disease.

Ketogenic diet

The ketogenic diet includes meat, poultry, fish, cheese, butter and cream, eggs, nuts and seeds, avocado, coconut, and olive oil.  It may be a good option if you don’t like calorie counting.  It helps reduce your appetite and food intake, reducing insulin levels and accelerating fat burning and weight loss.

You can fill your plate with low-calorie vegetables that contain fibre (slowing the absorption of sugar and fat), limit daily carbohydrate intake to 30-50 g and monitor ketone levels.

The Atkins Diet 

This comprises 60-70% fat, 20-30% protein and 5-10% carbs.  Low carbs trigger ketosis, promoting satiety, burning fat and increasing energy expenditure, meaning negative energy balance and weight loss.

The Atkins Diet contains high protein.  Unfortunately, there is no storage system for protein, with the excess usually converted into sugar, raising insulin growth factor-1 (IGF-1).

Your body produces IGF-I after eating sugar, carbs, meat, poultry, fish, milk and dairy products.  IGF-1 benefits muscles, brain and gut function, but high IGF-1 can cause diabetes, heart disease, arthritis, osteoporosis, thyroid disease and cancer, whilst lower levels are associated with health and longevity.

Interestingly, in a study comparing the Ornish (low-fat, plant-based) and Atkins (high-fat and protein) diets, the Atkins group lost more weight.

High omega 6:3 ratio increases the risk of metabolic diseases.  Our ancestors’ hunter-gatherer diet saw a ratio of 1:1, compared with our western diet of 20:1.  The vegan ratio is 15:1, vegetarian 10:1, meat-eater 7:1 and Mediterranean diet 4:1.  An intake of omega 3 balances the ratio and reduces the risk of disease.  A ratio of 4:1 has a positive impact on vascular, brain and eye health and is associated with longevity.

The ultimate metabolic prescription

The key elements of the Mediterranean diet include olives, bread, wine, cheese, vegetables, legumes like green beans, little meat and a preference for fish and seafood.

The Mediterranean diet is rich in fibre and antioxidants and low in animal fat, with an omega 6:3 ratio of 4:1 (optimal.)  It is 55-60% carbohydrates, 80% complex carbs (bread, pasta, rice), 10-15% protein, 60% animal origin (white meat, fish), and 25-30% fat, mostly olive oil.

Studies confirm that the Mediterranean diet reduces the risk of metabolic syndrome and vascular disease, remarkably decreasing abdominal obesity and triglyceride levels, increasing HDL (the good guy), and lowering blood pressure and blood glucose.

But, my friends, to enjoy the benefits of the Mediterranean diet, you should also include good physical activity and lower stress levels.  As always, please ask any questions in the Comment section below – and please do subscribe to the newsletter so that you don’t miss further vital information.  Thank you!



A ketogenic diet to lose weight and fight metabolic disease


Randomised trial comparing a very low carbohydrate diet and low-fat diet on body weight and cardiovascular risk factors on healthy women


Weight loss in metabolic syndrome given DASH diet


Vegan diet health benefits in metabolic syndrome


The Mediterranean Diet: A history of health