Balancing blood sugar levels is one of the key factors that affect energy levels, concentration, mood, and even sleep quality. Studies show that stable blood sugar is linked to less fatigue, less irritability and anxiety, better cognitive function, and even a lower risk of developing metabolic diseases in the long term.
In contrast, sharp fluctuations in blood sugar levels – rapid spikes followed by drops – can lead to fatigue, “energy crashes,” mental fog, and cravings for carbohydrates and sugar. For many people, this roller coaster begins in the very first minutes of the day.
Why is the morning so critical?
After the overnight fast, the body is especially sensitive to what enters it. Foods or drinks that contain sugar or fast-digesting carbohydrates may cause a sharp rise in blood glucose levels. This rise is usually accompanied by insulin secretion, followed by an equally sharp drop, which is felt as fatigue, hunger, and a craving for sweets.
This is where one of the most popular morning drinks comes into the picture, which many perceive as healthy: Coffee with oat milk.
Why oat milk specifically?
In recent years, oat milk has become a preferred choice in coffee shops – including in Israel. The neutral-sweet taste, creamy texture, and the fact that it is plant-based make it especially attractive for vegans, those sensitive to lactose, and anyone trying to “eat healthy.”
But clinical dietitians warn: When consumed on its own, especially in the morning, it may disrupt blood sugar balance.
According to registered dietitians, oat milk contains more carbohydrates and less protein and fat compared to cow’s milk or some other plant-based alternatives. This combination causes the sugar in it to be absorbed relatively quickly, without nutritional “brakes” to slow the process.
In addition, many oat milks contain vegetable oils and sometimes added sugar – even if in small amounts – which worsens the glycemic effect.
What happens in the body after such a coffee?
Drinking coffee with oat milk on an empty stomach mainly provides the body with carbohydrates and caffeine – without enough protein, fat, or dietary fiber that could stabilize blood sugar levels.
The possible result:
• A rapid rise in energy (sometimes felt as a “boost”)
• A sharp drop after about one to two hours
• Fatigue, mental fog, and decreased concentration
• Increased cravings for carbohydrates, sweets, or more coffee
For people with a tendency toward prediabetes, insulin resistance, or chronic fatigue – this effect may be especially pronounced.
So is oat milk “bad”?
Not necessarily. It is important to emphasize: Oat milk can be part of a healthy diet. The problem is not the drink itself – but the context in which it is consumed.
When it is used as a milk substitute within a balanced meal, its effect on blood sugar is much more moderate.
So how can you drink coffee with oat milk without harming blood sugar? The key is proper combination. Dietitians recommend:
• Not drinking such coffee as a substitute for breakfast
• Combining it with a protein source: Eggs, Greek yogurt, cheese, tofu
• Adding healthy fat: Nuts, almonds, avocado
• Including dietary fiber: Whole-grain bread, porridge, vegetables
Even a handful of nuts or a slice of whole-grain toast with a fatty spread can significantly change the blood sugar response.
Which alternatives are preferable for better sugar balance?
If blood sugar balance is especially important to you, dietitians point out several options:
• Soy milk – contains more protein and a bit more fat
• Unsweetened almond milk – low in carbohydrates
• Cow’s milk – the protein and fat in it balance the natural sugar
• A combination of half oat milk with another milk
The bottom line: Coffee with oat milk is not an enemy of health. But when it effectively becomes breakfast – it may lead to a roller coaster of sugar, energy, and cravings.
A simple combination of protein, fat, and fiber can turn that exact same drink into a much more balanced choice. Sometimes, a small change in a morning habit makes a big difference throughout the entire day.