An article written by Dr Edward Leatham, Consultant Cardiologist

Tags: VAT, LDL, Diet, Visceral Fat, CGM search website using Tags to find related stories.

Introduction

For decades, health advice has emphasised “low-fat” as the healthy option. Supermarket shelves are stacked with skimmed and semi-skimmed milk, marketed as the heart-friendly choice. Yet, in recent years, our understanding of nutrition has evolved. We now know that the relationship between dairy fat, heart health, and blood sugar regulation is more nuanced than once thought.

For people with carbohydrate sensitivity or non-diabetic hyperglycaemia (sometimes called “prediabetes”), the type of milk they put in their tea or coffee could make a surprising difference. Continuous glucose monitoring (CGM) is revealing patterns that traditional nutrition guidelines never captured.

A Real-Life Case: When Skimmed Milk Caused Glucose Spikes

One of our patients, a middle-aged woman using a continuous glucose monitor (CGM) to better understand her non-diabetic hyperglycaemia, noticed a puzzling pattern.

• Whenever she had tea with skimmed milk, her glucose levels spiked.
• Yet, when she switched to full-cream milk, the spikes disappeared.

This experience might sound counter-intuitive. After all, skimmed milk is supposed to be “lighter” and “healthier.” But what her CGM revealed was a lesson in physiology: the balance of macronutrients in a food can shape how our body processes sugar.

The Physiology: Why Fat Slows Sugar Absorption

The key difference between skimmed and full-cream milk is the fat content.

• Skimmed milk has most of the fat removed, leaving behind lactose, the natural sugar in milk, and protein.
• Full-cream milk still contains its natural fat, giving it a richer texture — and a very different metabolic effect.

When we drink milk, the lactose is broken down into glucose and galactose, both of which raise blood sugar. If fat is removed (as in skimmed milk), the carbohydrate load from lactose is delivered to the bloodstream more quickly.

When fat is present in a meal or drink:

1. Slower gastric emptying – Fat delays the speed at which food leaves the stomach, meaning the lactose sugars are released into the bloodstream more gradually.
2. Reduced glycaemic response – Because absorption is slower, blood glucose peaks are lower and steadier.
3. Better satiety – Meals containing fat often keep us fuller for longer, potentially reducing snacking later in the day.

In our patient’s case, the skimmed milk allowed the lactose sugars to hit her bloodstream rapidly, triggering a spike. Full-cream milk, with its fat, slowed that process and blunted the response.

Carbohydrate Sensitivity and Non-Diabetic Hyperglycaemia

Not everyone responds to carbohydrates in the same way. Some people can drink a glass of skimmed milk without noticeable impact. Others, especially those with:

• Insulin resistance
• Family history of diabetes
• Visceral fat accumulation
• Sedentary lifestyles

…may experience sharp glucose rises after even modest amounts of carbohydrate, including lactose.

This “carbohydrate sensitivity” is increasingly recognised, thanks to CGM technology. It helps explain why personalised nutrition is often more effective than one-size-fits-all advice.

What Do Large Studies Say About Dairy and Heart Health?

A major concern people raise about full-cream milk is the saturated fat content. For many years, public health guidelines advised limiting saturated fat to reduce the risk of heart disease. Yet, the evidence base has shifted.

Observational Studies

• The PURE study¹ followed over 130,000 people in 21 countries. Higher dairy intake (including full-fat) was associated with lower rates of heart disease and stroke, not higher.
• Meta-analyses of cohort studies² show that dairy fat, particularly from yoghurt and cheese, is not consistently linked with cardiovascular harm. In fact, some findings suggest a protective effect.
• Biomarkers of dairy fat in blood (such as odd-chain fatty acids) have been associated with reduced diabetes risk³,⁶.

Why might this be?

• Dairy fat contains specific fatty acids with unique metabolic effects⁴,⁵.
• Fermented dairy (like yoghurt and cheese) has additional benefits on the gut microbiome⁷.
• The overall food matrix — how proteins, fats, minerals, and vitamins interact — matters more than isolated saturated fat content.

In short: full-cream milk is not the villain it was once thought to be.

Balancing the Calorie Equation

Of course, full-cream milk does contain more calories than skimmed milk:

• Full-cream milk: ~65 kcal per 100 ml
• Semi-skimmed milk: ~45 kcal per 100 ml
• Skimmed milk: ~35 kcal per 100 ml

The extra calories come almost entirely from fat. But the carbohydrate — the lactose — is present in all types of milk, usually around 4–5 g per 100 ml.

For someone drinking several large lattes a day, the calorie difference could add up. In the context of weight management, these extra calories matter.

However, if switching from skimmed to full-cream milk:

• Prevents blood sugar spikes from lactose
• Reduces cravings later in the day
• Helps avoid snacking or overeating

…the net effect may actually be neutral or even beneficial for weight control.

💡 Tip for Readers: How Much Lactose and Calories Are in Your Milk?

Milk naturally contains lactose, a sugar (carbohydrate), at similar levels regardless of fat content. The real difference is the fat and calorie content.

🔎 Key point:

• Lactose (the milk sugar) is present in all types of milk at about 4–5 g per 100 ml.
• Removing fat doesn’t reduce the sugar. In fact, without fat to slow digestion, skimmed milk can sometimes cause faster glucose spikes.

Could Full-Cream Milk Be the “Lesser of Two Evils”?

For someone with carbohydrate sensitivity:

• A teaspoon of sugar in tea plus skimmed milk = rapid glucose spike from both sugar and lactose
• Tea with full-cream milk, no sugar = gentler, steadier response

In this scenario, full-cream milk is not only the healthier option, but also the one that helps the individual stick to long-term lifestyle changes.

We must also remember that fat does not stimulate insulin to the same degree as carbohydrate. By reducing glycaemic load from lactose, full-cream milk may help preserve insulin sensitivity.

Individualised Nutrition: The Role of CGM

The most exciting development in recent years is the personalisation of nutrition using CGM.

• CGM shows real-time data on how specific foods affect blood sugar.
• Two people can drink the same glass of milk and have completely different glucose responses.
• It allows for experiments, such as comparing skimmed vs. full-cream milk, and choosing what works best.

Our patient’s experience is one example of how self-tracking can challenge conventional advice and lead to more effective, tailored solutions.

Practical Guidance for Patients

So, what should you do if you have non-diabetic hyperglycaemia or suspect carbohydrate sensitivity?

1. Don’t fear full-cream milk. It may actually help stabilise your blood sugars by slowing lactose absorption.
2. Use CGM if available. Try skimmed, semi-skimmed, and full-cream milk on separate days and compare the results.
3. Watch portion sizes. If you only use a splash in tea or coffee, the calorie difference is minimal. If you drink large milk-based drinks, be mindful of the cumulative calories.
4. Avoid adding sugar. Full-cream milk works best when it replaces, rather than accompanies, added sugar.
5. Look at your whole diet. Switching milk type is one piece of the puzzle. Fibre intake, protein distribution, physical activity, and weight management all play major roles.
6. Consult your clinician. Especially if you have established diabetes, high cholesterol, or cardiovascular disease, as your care may need more individual adjustments.

Wider Implications: Rethinking Old Nutrition Advice

This discussion reflects a broader trend in nutrition science:

• Low-fat diets once dominated public health messaging.
• Yet, the rise of obesity and type 2 diabetes coincided with increased consumption of “low-fat” processed foods — often loaded with sugars and refined starches⁸.
• We now recognise that dietary fat, in moderation and in whole-food sources, is not inherently harmful.
• Instead, ultra-processed carbohydrates and excess calorie intake are the real culprits in metabolic disease⁹.

Full-cream milk sits within this shift. Rather than stripping foods of their natural fat and inadvertently worsening their glycaemic impact (by leaving behind rapidly absorbed lactose), we may be better served by embracing them in their more natural form.

Conclusion: A Healthier Option for Some

For people with carbohydrate sensitivity or non-diabetic hyperglycaemia, full-cream milk in tea or coffee may be healthier than skimmed milk. The presence of natural dairy fat slows the absorption of lactose, the carbohydrate in milk, reducing glucose spikes and improving satiety.

Large studies show that dairy fat is not linked with higher heart disease risk, and in some cases may be protective¹–⁷. The calorie difference between milk types matters in large volumes, but in everyday tea or coffee use it is usually small.

The key is personalisation. Tools like CGM empower individuals to test and discover what works for their metabolism. For many, the results may support a return to full-cream milk — a simple, satisfying, and surprisingly healthy choice.

References

1. Dehghan M, Mente A, Rangarajan S, Sheridan P, Mohan V, Iqbal R, et al. Association of dairy intake with cardiovascular disease and mortality in 21 countries from five continents (PURE): a prospective cohort study. Lancet. 2018;392(10161):2288–97.
2. Guo J, Astrup A, Lovegrove JA, Gijsbers L, Givens DI, Soedamah-Muthu SS. Milk and dairy consumption and risk of cardiovascular diseases and all-cause mortality: dose–response meta-analysis of prospective cohort studies. Eur J Epidemiol. 2017;32(4):269–87.
3. Chen M, Sun Q, Giovannucci E, Mozaffarian D, Manson JE, Willett WC, et al. Dairy consumption and risk of type 2 diabetes: 3 cohorts of US adults and an updated meta-analysis. BMC Med. 2014;12:215.
4. Drouin-Chartier JP, Brassard D, Tessier-Grenier M, Côté JA, Labonté ME, Desroches S, et al. Systematic review of the association between dairy product consumption and risk of cardiovascular-related clinical outcomes. Adv Nutr. 2016;7(6):1026–40.
5. Drouin-Chartier JP, Côté JA, Labonté ME, Brassard D, Tessier-Grenier M, Desroches S, et al. Comprehensive review of the impact of dairy foods and dairy fat on cardiometabolic risk. Adv Nutr. 2019;10(5):848–63.
6. Gijsbers L, Ding EL, Malik VS, de Goede J, Geleijnse JM, Soedamah-Muthu SS. Consumption of dairy foods and diabetes incidence: a dose–response meta-analysis of observational studies. Am J Clin Nutr. 2016;103(4):1111–24.
7. Thorning TK, Raben A, Tholstrup T, Soedamah-Muthu SS, Givens I, Astrup A. Milk and dairy products: good or bad for human health? An assessment of the totality of scientific evidence. Food Nutr Res. 2016;60:32527.
8. Stanhope KL. Sugar consumption, metabolic disease and obesity: The state of the controversy. Crit Rev Clin Lab Sci. 2016;53(1):52–67.
9. Tremblay A, Gilbert JA. Human obesity: is visceral obesity the cause or the consequence of metabolic dysregulation? J Physiol. 2009;587(21):4113–25.

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